Improves ml_model package endpoints

See merge request https://gitlab.com/gitlab-org/gitlab/-/merge_requests/138787



Merged-by: John Mason <9717668-johnmason@users.noreply.gitlab.com>
Approved-by: Corinna Gogolok <cgogolok@gitlab.com>
Approved-by: John Mason <9717668-johnmason@users.noreply.gitlab.com>
Reviewed-by: Corinna Gogolok <cgogolok@gitlab.com>
Reviewed-by: Eduardo Bonet <ebonet@gitlab.com>
Co-authored-by: Eduardo Bonet <ebonet@gitlab.com>
Co-authored-by: Corinna Gogolok <cgogolok@gitlab.com>