Add missing keyword_init to Struct.new in Gitaly server.rb

What does this MR do and why?

After !163430 (merged) got merged. We had some master:broken failures like: #482724 (comment 2087872420) and #482725 (comment 2087872586). The assumption here is that the Gitlab::GitalyClient::ServerService gets called multiple times and it caches an unexpected response in Rails.cache.

There was an attempt to fix some of those errors: !164887 (merged), but the clean_gitlab_redis_cache did not solve the original problem.

  1) API::WebCommits GET /web_commits/public_key when Gitaly is unavailable does not cache the public key
     Failure/Error:
       Rails.cache.fetch(GITALY_PUBLIC_KEY_CACHE_KEY, expires_in: 1.hour.to_i, skip_nil: true) do
         { public_key: server_signature_public_key }
       end

       (<ActiveSupport::Cache::NullStore>).fetch("gitaly_public_key", {:expires_in=>3600, :skip_nil=>true})
           expected: 0 times with arguments: ("gitaly_public_key", {:expires_in=>3600, :skip_nil=>true})
           received: 1 time with arguments: ("gitaly_public_key", {:expires_in=>3600, :skip_nil=>true})
     # ./lib/api/web_commits.rb:35:in `cache_public_key'
     # ./lib/api/web_commits.rb:54:in `block in <class:WebCommits>'
     # ./ee/lib/gitlab/middleware/ip_restrictor.rb:14:in `block in call'
     # ./lib/gitlab/ip_address_state.rb:11:in `with'
     # ./ee/lib/gitlab/middleware/ip_restrictor.rb:13:in `call'
     # ./lib/api/api_guard.rb:219:in `call'
     # ./lib/gitlab/middleware/sidekiq_shard_awareness_validation.rb:20:in `block in call'
     # ./lib/gitlab/sidekiq_sharding/validator.rb:42:in `enabled'
     # ./lib/gitlab/middleware/sidekiq_shard_awareness_validation.rb:20:in `call'
     # ./lib/gitlab/middleware/memory_report.rb:13:in `call'
     # ./lib/gitlab/middleware/speedscope.rb:13:in `call'
     # ./lib/gitlab/query_limiting/middleware.rb:17:in `block in call'
     # ./lib/gitlab/query_limiting/transaction.rb:48:in `run'
     # ./lib/gitlab/query_limiting/middleware.rb:16:in `call'
     # ./lib/gitlab/database/load_balancing/rack_middleware.rb:23:in `call'
     # ./lib/gitlab/middleware/go.rb:22:in `call'
     # ./lib/gitlab/etag_caching/middleware.rb:21:in `call'
     # ./lib/gitlab/middleware/query_analyzer.rb:11:in `block in call'
     # ./lib/gitlab/database/query_analyzer.rb:40:in `within'
     # ./lib/gitlab/middleware/query_analyzer.rb:11:in `call'
     # ./lib/gitlab/middleware/multipart.rb:173:in `call'
     # ./lib/gitlab/middleware/read_only/controller.rb:50:in `call'
     # ./lib/gitlab/middleware/read_only.rb:18:in `call'
     # ./lib/gitlab/middleware/unauthenticated_session_expiry.rb:18:in `call'
     # ./lib/gitlab/middleware/strip_cookies.rb:29:in `call'
     # ./lib/gitlab/middleware/same_site_cookies.rb:27:in `call'
     # ./lib/gitlab/middleware/path_traversal_check.rb:37:in `call'
     # ./lib/gitlab/middleware/handle_malformed_strings.rb:21:in `call'
     # ./lib/gitlab/middleware/basic_health_check.rb:25:in `call'
     # ./lib/gitlab/middleware/handle_ip_spoof_attack_error.rb:25:in `call'
     # ./lib/gitlab/middleware/request_context.rb:15:in `call'
     # ./lib/gitlab/middleware/webhook_recursion_detection.rb:15:in `call'
     # ./config/initializers/fix_local_cache_middleware.rb:11:in `call'
     # ./lib/gitlab/middleware/compressed_json.rb:44:in `call'
     # ./lib/gitlab/middleware/static.rb:11:in `call'
     # ./lib/gitlab/testing/clear_process_memory_cache_middleware.rb:13:in `call'
     # ./lib/gitlab/testing/request_inspector_middleware.rb:35:in `call'
     # ./lib/gitlab/testing/robots_blocker_middleware.rb:30:in `call'
     # ./lib/gitlab/testing/request_blocker_middleware.rb:47:in `call'
     # ./lib/gitlab/middleware/rack_multipart_tempfile_factory.rb:19:in `call'
     # ./lib/gitlab/middleware/sidekiq_web_static.rb:20:in `call'
     # ./lib/gitlab/metrics/requests_rack_middleware.rb:79:in `call'
     # ./spec/requests/api/web_commits_spec.rb:65:in `block (4 levels) in <main>'
     # ./spec/spec_helper.rb:471:in `block (3 levels) in <top (required)>'
     # ./lib/gitlab/sidekiq_sharding/validator.rb:42:in `enabled'
     # ./spec/spec_helper.rb:470:in `block (2 levels) in <top (required)>'
     # ./spec/spec_helper.rb:465:in `block (3 levels) in <top (required)>'
     # ./spec/support/sidekiq_middleware.rb:9:in `with_sidekiq_server_middleware'
     # ./spec/spec_helper.rb:456:in `block (2 levels) in <top (required)>'
     # ./spec/spec_helper.rb:452:in `block (3 levels) in <top (required)>'
     # ./lib/gitlab/application_context.rb:92:in `with_raw_context'
     # ./spec/spec_helper.rb:452:in `block (2 levels) in <top (required)>'
     # ./spec/spec_helper.rb:268:in `block (2 levels) in <top (required)>'
     # ./spec/support/system_exit_detected.rb:7:in `block (2 levels) in <main>'
     # ./spec/support/redis.rb:17:in `block (3 levels) in <main>'
     # ./spec/support/fast_quarantine.rb:22:in `block (2 levels) in <main>'
     # ./spec/support/database/prevent_cross_joins.rb:106:in `block (3 levels) in <main>'
     # ./spec/support/database/prevent_cross_joins.rb:60:in `with_cross_joins_prevented'
     # ./spec/support/database/prevent_cross_joins.rb:106:in `block (2 levels) in <main>'

  2) API::WebCommits GET /web_commits/public_key when Gitaly is unavailable returns service unavailable
     Failure/Error: expect(response).to have_gitlab_http_status(:service_unavailable)
       expected the response to have status code :service_unavailable but it was 200. The response was: {"public_key":{"public_key":null,"error":true}}
     # ./spec/requests/api/web_commits_spec.rb:71:in `block (4 levels) in <main>'
     # ./spec/spec_helper.rb:471:in `block (3 levels) in <top (required)>'
     # ./lib/gitlab/sidekiq_sharding/validator.rb:42:in `enabled'
     # ./spec/spec_helper.rb:470:in `block (2 levels) in <top (required)>'
     # ./spec/spec_helper.rb:465:in `block (3 levels) in <top (required)>'
     # ./spec/support/sidekiq_middleware.rb:9:in `with_sidekiq_server_middleware'
     # ./spec/spec_helper.rb:456:in `block (2 levels) in <top (required)>'
     # ./spec/spec_helper.rb:452:in `block (3 levels) in <top (required)>'
     # ./lib/gitlab/application_context.rb:92:in `with_raw_context'
     # ./spec/spec_helper.rb:452:in `block (2 levels) in <top (required)>'
     # ./spec/spec_helper.rb:268:in `block (2 levels) in <top (required)>'
     # ./spec/support/system_exit_detected.rb:7:in `block (2 levels) in <main>'
     # ./spec/support/redis.rb:17:in `block (3 levels) in <main>'
     # ./spec/support/fast_quarantine.rb:22:in `block (2 levels) in <main>'
     # ./spec/support/database/prevent_cross_joins.rb:106:in `block (3 levels) in <main>'
     # ./spec/support/database/prevent_cross_joins.rb:60:in `with_cross_joins_prevented'
     # ./spec/support/database/prevent_cross_joins.rb:106:in `block (2 levels) in <main>'

Finished in 59.5 seconds (files took 1 minute 11.71 seconds to load)
2 examples, 2 failures

Failed examples:

rspec ./spec/requests/api/web_commits_spec.rb:60 # API::WebCommits GET /web_commits/public_key when Gitaly is unavailable does not cache the public key
rspec ./spec/requests/api/web_commits_spec.rb:68 # API::WebCommits GET /web_commits/public_key when Gitaly is unavailable returns service unavailable

  1) Gitaly::Server#server_signature_error? when the server signature raises a GRPC error returns an error and no public_key
     Failure/Error: expect(server.server_signature_public_key).to be_nil

       expected: nil
            got: {:error=>true, :public_key=>nil}
     # ./spec/lib/gitaly/server_spec.rb:165:in `block (4 levels) in <main>'
     # ./spec/spec_helper.rb:471:in `block (3 levels) in <top (required)>'
     # ./lib/gitlab/sidekiq_sharding/validator.rb:42:in `enabled'
     # ./spec/spec_helper.rb:470:in `block (2 levels) in <top (required)>'
     # ./spec/spec_helper.rb:465:in `block (3 levels) in <top (required)>'
     # ./spec/support/sidekiq_middleware.rb:9:in `with_sidekiq_server_middleware'
     # ./spec/spec_helper.rb:456:in `block (2 levels) in <top (required)>'
     # ./spec/spec_helper.rb:452:in `block (3 levels) in <top (required)>'
     # ./lib/gitlab/application_context.rb:92:in `with_raw_context'
     # ./spec/spec_helper.rb:452:in `block (2 levels) in <top (required)>'
     # ./spec/spec_helper.rb:268:in `block (2 levels) in <top (required)>'
     # ./spec/support/system_exit_detected.rb:7:in `block (2 levels) in <main>'
     # ./spec/support/fast_quarantine.rb:22:in `block (2 levels) in <main>'
     # ./spec/support/database/prevent_cross_joins.rb:106:in `block (3 levels) in <main>'
     # ./spec/support/database/prevent_cross_joins.rb:60:in `with_cross_joins_prevented'
     # ./spec/support/database/prevent_cross_joins.rb:106:in `block (2 levels) in <main>'

Finished in 50.53 seconds (files took 1 minute 11.92 seconds to load)
1 example, 1 failure

Failed examples:

rspec ./spec/lib/gitaly/server_spec.rb:164 # Gitaly::Server#server_signature_error? when the server signature raises a GRPC error returns an error and no public_key

Resolves: gitlab-org/quality/engineering-productivity/master-broken-incidents#8259 (closed)

MR acceptance checklist

Please evaluate this MR against the MR acceptance checklist. It helps you analyze changes to reduce risks in quality, performance, reliability, security, and maintainability.