feat(api): support the new registry protection rule endpoint

[nejch]

Changes

Gitlab changed from the REST container registry protection endpoint from
/projects/{project_id}/registry/protection/rules
to
/projects/{project_id}/registry/repository/protection/rules

Not great, but can't blame them as it's still behind a feature flag. This adds the new endpoint pretty much with a copy paste. As of GitLab 17.7 the old endpoint no longer works.

Looked at a few ways to deprecate all the methods but not sure it's worth it, but might do it in a follow-up.
https://www.geeksforgeeks.org/attaching-a-decorator-to-all-functions-within-a-class-in-python/ might work.

Documentation and testing

Please consider whether this PR needs documentation and tests. This is not required, but highly appreciated:

• Documentation in the matching docs section
• Unit tests and/or functional tests

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 96.68%. Comparing base (9439132) to head (b35389c).
Report is 1 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #3067   +/-   ##
=======================================
  Coverage   96.67%   96.68%           
=======================================
  Files          95       96    +1     
  Lines        6197     6213   +16     
=======================================
+ Hits         5991     6007   +16     
  Misses        206      206           

Flag	Coverage Δ
api_func_v4	82.68% <100.00%> (-0.06%)	⬇️
cli_func_v4	82.69% <100.00%> (+0.04%)	⬆️
unit	89.02% <100.00%> (+0.02%)	⬆️

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Files with missing lines	Coverage Δ
gitlab/v4/objects/__init__.py	100.00% <100.00%> (ø)
gitlab/v4/objects/projects.py	98.84% <100.00%> (+<0.01%)	⬆️
...v4/objects/registry_repository_protection_rules.py	100.00% <100.00%> (ø)