Follow-up refactor and backport from "Geo: Exclude expired job artifacts from syncing and counts"

The following discussions from !5380 (merged) should be addressed:

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

  I don't feel this is Geo-only, in fact, it should be in Core, and we could use it in app/models/lfs_object.rb, app/models/upload.rb, app/models/ci/job_artifact.rb. Or should we defer doing this to a later MR?

• @toon started a discussion: (+4 comments)

  Should we port this to CE? I'd say, probably not worth the effort right now.