Merge branch 'stomlinson/speed-up-db-schema-spec' into 'master'

Analyze db/schema_spec.rb with stackprof and improve spec runtime

See merge request https://gitlab.com/gitlab-org/gitlab/-/merge_requests/167958



Merged-by: Matt Kasa <mkasa@gitlab.com>
Approved-by: Matt Kasa <mkasa@gitlab.com>
Reviewed-by: Krasimir Angelov <kangelov@gitlab.com>
Co-authored-by: Simon Tomlinson <stomlinson@gitlab.com>