This is no longer possible in future go-git versions, so lets hardcode it
Reviewed-on: https://codeberg.org/forgejo/forgejo/pulls/6488
Reviewed-by: Earl Warren <earl-warren@noreply.codeberg.org>
Co-authored-by: Gusted <postmaster@gusted.xyz>
Co-committed-by: Gusted <postmaster@gusted.xyz>
