Protected Branches Group Level

Feature Request to create the protected_branches attr for the Group class.

The ability exists over API to query this: (docs)

curl --header "PRIVATE-TOKEN: <your_access_token>" \
  --url "https://gitlab.example.com/api/v4/groups/5/protected_branches"

e.g.

>>> group = gl.groups.get('56')
>>> pb = group.protectedbranches.list(get_all=True)
>>> pb

[
  {
    "id": 1,
    "name": "main",
    "push_access_levels": [
      {
        "id":  1,
        "access_level": 40,
        "user_id": null,
        "group_id": 1234,
        "access_level_description": "Maintainers"
      }
    ],
    "merge_access_levels": [
      {
        "id":  1,
...

ref: https://gitlab.com/gitlab-security-oss/cis/gitlabcis/-/issues/125

Specifications

python-gitlab version: 5.6.0
Gitlab server version (or gitlab.com): GitLab Enterprise Edition 17.11.0-pre 76ac92593a5