Ensure removed workers are also removed from every sidekiq worker spec

What does this MR do and why?

During review of !124430 (comment 1442035877) it was noticed that removed sidekiq workers still showed up in spec/workers/every_sidekiq_worker_spec.rb.

This MR ensures that Ensure removed workers are also removed from every sidekiq worker spec.

Example failure:

Failures:

  1) Every Sidekiq worker retries defines `retry_exceptions` only for existing workers
     Failure/Error: expect(removed_workers).to be_empty, message

       The following workers no longer exist but are defined in `retry_exceptions`:

       - Analytics::InstanceStatistics::CounterJobWorker
       - ArchiveTraceWorker
       - BuildFinishedWorker
       - Clusters::Cleanup::AppWorker
       - Deployments::FinishedWorker
       - Deployments::ForwardDeploymentWorker
       - Deployments::SuccessWorker
       - GitGarbageCollectWorker
       - MergeRequests::AssigneesChangeWorker
       - Namespaces::RefreshRootStatisticsWorker
       - ProjectScheduleBulkRepositoryShardMovesWorker
       - ProjectUpdateRepositoryStorageWorker
       - SnippetScheduleBulkRepositoryShardMovesWorker
       - SnippetUpdateRepositoryStorageWorker
       - WebHooks::DestroyWorker

       Make sure to remove them from `retry_exceptions` because their definition is unnecessary.

This MR removes all unnecessary definitions for removed workers.

• Analytics::InstanceStatistics::CounterJobWorker
• ArchiveTraceWorker
• BuildFinishedWorker
• Clusters::Cleanup::AppWorker
• Deployments::FinishedWorker
• Deployments::ForwardDeploymentWorker
• Deployments::SuccessWorker
• GitGarbageCollectWorker
• MergeRequests::AssigneesChangeWorker
• Namespaces::RefreshRootStatisticsWorker
• ProjectScheduleBulkRepositoryShardMovesWorker
• ProjectUpdateRepositoryStorageWorker
• SnippetScheduleBulkRepositoryShardMovesWorker
• SnippetUpdateRepositoryStorageWorker
• WebHooks::DestroyWorker

How to set up and validate locally

bin/rspec spec/workers/every_sidekiq_worker_spec.rb

FOSS_ONLY=1 bin/rspec spec/workers/every_sidekiq_worker_spec.rb

MR acceptance checklist

This checklist encourages us to confirm any changes have been analyzed to reduce risks in quality, performance, reliability, security, and maintainability.

• I have evaluated the MR acceptance checklist for this MR.