Merge branch 'update-enqueue_index' into 'master'

Switch indexing button to background job

See merge request https://gitlab.com/gitlab-org/gitlab/-/merge_requests/160231



Merged-by: Madelein van Niekerk <mvanniekerk@gitlab.com>
Approved-by: Tomas Vik <tvik@gitlab.com>
Approved-by: Madelein van Niekerk <mvanniekerk@gitlab.com>
Reviewed-by: Dmitry Gruzd <dgruzd@gitlab.com>
Reviewed-by: Terri Chu <tchu@gitlab.com>
Reviewed-by: Madelein van Niekerk <mvanniekerk@gitlab.com>
Co-authored-by: Dmitry Gruzd <dgruzd@gitlab.com>