Merge branch 'improve-projects-not-indexed-query' into 'master'

Improve rake elastic:projects_not_indexed query

See merge request https://gitlab.com/gitlab-org/gitlab/-/merge_requests/126694



Merged-by: Terri Chu <tchu@gitlab.com>
Approved-by: Halil Coban <hcoban@gitlab.com>
Approved-by: Terri Chu <tchu@gitlab.com>
Reviewed-by: Halil Coban <hcoban@gitlab.com>
Co-authored-by: Dmitry Gruzd <dgruzd@gitlab.com>