In forgejo/forgejo!2834 and forgejo/forgejo!5307 it was made so it's no longer possible to modify and delete internal reference, not having this restriction lead to broken pull requests when people used something like `git push --mirror`. However it now still leads to problem with that command as the git client tries to delete such references. We can solve this by using git's `receive.hideRefs` to make this ref read-only and avoid advertising it when someone does `git push --mirror`.
Resolvesforgejo/forgejo#9942
Reviewed-on: https://codeberg.org/forgejo/forgejo/pulls/10015
Reviewed-by: Mathieu Fenniak <mfenniak@noreply.codeberg.org>
Co-authored-by: Gusted <postmaster@gusted.xyz>
Co-committed-by: Gusted <postmaster@gusted.xyz>
