Renames release to publish

What does this MR do?

While working on !1245 (merged) I found release to be a bit confusing, since for these manual jobs they are not run until a publish command is issues in release tools

• https://gitlab.com/gitlab-org/release-tools/-/blob/master/lib/release_tools/services/publish_service/cng_publish_service.rb#L13
• https://gitlab.com/gitlab-org/release/docs/-/tree/master/release_manager#monthly-patch-and-security-releases-commands

It would be a bit clearer if we use publish for the stage name instead of release.

Related issues

Checklist

See Definition of done.

For anything in this list which will not be completed, please provide a reason in the MR discussion

Required

• Merge Request Title, and Description are up to date, accurate, and descriptive
• MR targeting the appropriate branch
• MR has a green pipeline on GitLab.com

Expected (please provide an explanation if not completing)

• Test plan indicating conditions for success has been posted and passes
• Documentation created/updated
• Integration tests added to GitLab QA
• The impact any change in container size has should be evaluated