Follow-up from "Increase parallelism of geo repository sync worker"

The following discussions from !2351 (merged) should be addressed:

• @smcgivern started a discussion:

  We might want to extract this to a module in future. No need now, though.

• @smcgivern started a discussion:

  Oh, and this 🙂

• @rspeicher started a discussion: (+1 comment)

  We now repeat this fairly complex bit of business from app/workers/geo_file_download_dispatch_worker.rb -- would it be worth putting this in a helper somewhere (though I couldn't begin to propose where)?

  Can be addressed in a new issue.

• @DouweM started a discussion: (+1 comment)

  Is there anything we can do to reduce the duplication between this and the mirroring logic, so if we ever improve the one, the other also benefits?

• @DouweM started a discussion: (+3 comments)

  Instead of looping here, could we run this scheduler more often (every minute, like https://gitlab.com/gitlab-org/gitlab-ee/blob/master/lib/gitlab/mirror.rb#L6) and have each individual project sync worker check if it makes sense to run the scheduler again (like https://gitlab.com/gitlab-org/gitlab-ee/blob/master/app/workers/repository_update_mirror_worker.rb#L37)?