Draft: Remove metrics category from service ping

What does this MR do and why?

All Category:Metrics project-level features were removed in %16.0. We don't need corresponding service ping data anymore.

Changes:

• Removes grafana_integrated_projects & issues_with_embedded_grafana_charts_approx metrics from service ping after removal of grafana dashboard features.
• Formally removes issues_created_gitlab_alerts & issues_created_manually_from_alerts, since they were previously disabled due to poor performance and are not used anywhere. See Remove metrics that take long time from Service... (!90356 - merged)

Related issues:

• Metrics: Remove service ping metrics (#397136)
• Service Ping metric counts.issues_created_gitla... (#365482)

Details for groupanalytics instrumentation review:

Verification that metrics can be removed from version app

syasonik@macbook-pro version.gitlab.com % bundle exec rspec spec/controllers/usage_data_controller_spec.rb
warning: parser/current is loading parser/ruby30, which recognizes3.0.4-compliant syntax, but you are running 3.0.5.
Please see https://github.com/whitequark/parser#compatibility-with-ruby-mri.
Run options: exclude {:redis=>true}

Randomized with seed 28517
............................

Finished in 4.5 seconds (files took 3.33 seconds to load)
28 examples, 0 failures

Randomized with seed 28517

Coverage report generated for RSpec to /Users/syasonik/workspace/version.gitlab.com/coverage. 639 / 2337 LOC (27.34%) covered.

syasonik@macbook-pro version.gitlab.com % git diff
diff --git a/spec/support/service_ping/ce_standard_subscription_operational_optional.json b/spec/support/service_ping/ce_standard_subscription_operational_optional.json
index dffbe7e..9f6aeb4 100644
--- a/spec/support/service_ping/ce_standard_subscription_operational_optional.json
+++ b/spec/support/service_ping/ce_standard_subscription_operational_optional.json
@@ -62,16 +62,12 @@
     "kubernetes_agents": 0,
     "kubernetes_agents_with_token": 0,
     "in_review_folder": 17,
-    "grafana_integrated_projects": 0,
     "groups": 10,
     "issues": 531,
     "issues_created_from_gitlab_error_tracking_ui": 0,
     "issues_with_associated_zoom_link": 0,
     "issues_using_zoom_quick_actions": 0,
-    "issues_with_embedded_grafana_charts_approx": 0,
     "issues_created_from_alerts": 0,
-    "issues_created_gitlab_alerts": 0,
-    "issues_created_manually_from_alerts": 0,
     "incident_issues": 0,
     "alert_bot_incident_issues": 0,
     "incident_labeled_issues": 0,
diff --git a/spec/support/service_ping/ee_standard_subscription_operational_optional.json b/spec/support/service_ping/ee_standard_subscription_operational_optional.json
index 16b06cc..7a1ecaa 100644
--- a/spec/support/service_ping/ee_standard_subscription_operational_optional.json
+++ b/spec/support/service_ping/ee_standard_subscription_operational_optional.json
@@ -79,16 +79,12 @@
     "kubernetes_agents": 0,
     "kubernetes_agents_with_token": 0,
     "in_review_folder": 17,
-    "grafana_integrated_projects": 0,
     "groups": 10,
     "issues": 531,
     "issues_created_from_gitlab_error_tracking_ui": 0,
     "issues_with_associated_zoom_link": 0,
     "issues_using_zoom_quick_actions": 0,
-    "issues_with_embedded_grafana_charts_approx": 0,
     "issues_created_from_alerts": 0,
-    "issues_created_gitlab_alerts": 0,
-    "issues_created_manually_from_alerts": 0,
     "incident_issues": 0,
     "alert_bot_incident_issues": 0,
     "incident_labeled_issues": 0,

Verification that metrics are removed from sisense dashboards

Deprecated metric	Found/removed any?	Search after
grafana_integrated_projects	✅
issues_with_embedded_grafana_charts_approx	✅
issues_created_gitlab_alerts	👎
issues_created_manually_from_alerts	👎

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.

Related to #397136