Deprecate legacy Geo Prometheus repository checks metrics

Deprecation Summary

Following the migration of projects to the Geo self-service framework we have removed the support for repository checks using git fsck on Geo secondary sites.

The following Geo-related [Prometheus](https://docs.gitlab.com/ee/administration/monitoring/prometheus/) metrics are deprecated and will be removed in 18.0.

The table below lists the deprecated metrics and their respective replacements. The replacements are available in GitLab 16.3.0 and later.

Deprecated metric	Replacement metric
geo_repositories_count	geo_project_repositories_count
geo_repositories_checked_count	None available
geo_repositories_checked_failed_count	None available

Breaking Change?

Yes

Affected Topology

All Geo deployments

Affected Tier

• Premium
• Ultimate

### Deprecation Milestone

17.4

Planned Removal Milestone

GitLab 18.0

Links

Deprecation announcement and implementation: !164940 (merged)

Checklists

Click to expand

Labels

• This issue is labeled deprecation, and with the relevant `~devops::`, `~group::`, and `~Category:` labels. - [ ] This issue is labeled breaking change if the removal of the deprecated item will be a breaking change.

Timeline

Please add links to the relevant merge requests.

• As soon as possible, but no later than the third milestone preceding the major release (for example, given the following release schedule: 14.8, 14.9, 14.10, 15.0 – 14.8 is the third milestone preceding the major release):
  • A deprecation announcement entry has been created so the deprecation will appear in release posts and on the general deprecation page.
  • Documentation has been updated to mark the feature as deprecated.
• On the major milestone:
  • The deprecated item has been removed.
  • If the removal of the deprecated item is a breaking change, the merge request is labeled breaking change.

Mentions

• Your stage's stable counterparts have been @mentioned on this issue. For example, Customer Support, Customer Success (Technical Account Manager), Product Marketing Manager.
  • To see who the stable counterparts are for a product team visit product categories
    • If there is no stable counterpart listed for Sales/CS please mention @timtams
    • If there is no stable counterpart listed for Support please mention @gitlab-com/support/managers
    • If there is no stable counterpart listed for Marketing please mention @cfoster3
• Your GPM or Director has been @mentioned so that they are aware of planned deprecations.