Merge branch 'ph/514923/mrApproversFilterHiddenUsersDefaultEnabled' into 'master'

Enable `mr_approvers_filter_hidden_users` by default

See merge request https://gitlab.com/gitlab-org/gitlab/-/merge_requests/180592



Merged-by: Joe Woodward <jwoodward@gitlab.com>
Approved-by: Amy Qualls <aqualls@gitlab.com>
Approved-by: Joe Woodward <jwoodward@gitlab.com>
Co-authored-by: Amy Qualls <aqualls@gitlab.com>
Co-authored-by: Phil Hughes <me@iamphill.com>