Reduce the number of series for rails_request SLIs
Reduce the number of series for rails_request SLIs
This removes 1960 series in total for the following metrics:
gitlab_sli_rails_request_total
gitlab_sli_rails_request_error_total
gitlab_sli_rails_request_apdex_total
gitlab_sli_rails_request_apdex_success_total
We do this by not initializing the metrics for endpoints that haven't been used on GitLab.com in a month.
These endpoints include a bunch of admin endpoints, but also endpoints that aren't actually reachable.
This was discussed in gitlab-org/quality/engineering-productivity/master-broken-incidents#7229 (comment 1992920196)