In GitLab 16.1,
https://gitlab.com/gitlab-org/gitlab/-/merge_requests/123228 disabled
the Prometheus metrics in the GraphQL generic tracer under a feature
flag since it was generating high-cardiunality metrics that weren't
being used.

We now drop this module entirely now that it's been replaced with
MetricsTracer.

Relates to https://gitlab.com/gitlab-org/gitlab/-/issues/345396

Changelog: changed