Remove high cardinality Prometheus metric
Remove high cardinality Prometheus metric

The metric was used to correlate Gitaly requests to the Rails controller
and action combination. However, Kibana provides better observability in
this specific metric, and can handle hig cardinality much better.

There's no dashboard in Grafana that currently depends on this metric
being exposed.

mmkassem/gitlabhq,stoplightio/gitlabhq,stoplightio/gitlabhq,mmkassem/gitlabhq,stoplightio/gitlabhq,stoplightio/gitlabhq,mmkassem/gitlabhq,mmkassem/gitlabhq