text: Title: Type hints: re-add `py.typed` marker [regression]
  Body: ## Description of the problem, including code/CLI snippet
  
  ```
  (.venv) C:\Build\project>echo import gitlab > bug.py
  
  (.venv) C:\Build\project>mypy bug.py
  ```
  
  ## Expected Behavior
  
  No `mypy` error
  
  ## Actual Behavior
  
  ```
  bug.py:1: error: Skipping analyzing "gitlab": module is installed, but missing library stubs or py.typed marker  [import-untyped]
  bug.py:1: note: See https://mypy.readthedocs.io/en/stable/running_mypy.html#missing-imports
  bug.py:1: note: See https://mypy.rtfd.io/en/stable/_refs.html#code-import-untyped for more info
  Found 1 error in 1 file (checked 1 source file)
  ```
  
  ## Specifications
  
    - python-gitlab version: 4.1.0 and 4.0.0 (not before 4)
    - API version you are using (v3/v4): n/a
    - Gitlab server version (or gitlab.com): n/a
  
  ## Relevant info
  
  > Mypy will not try inferring the types of any 3rd party libraries you have installed unless they either have declared themselves to be [PEP 561 compliant stub package](https://mypy.readthedocs.io/en/stable/installed_packages.html#installed-packages) (e.g. with a py.typed file) or have registered themselves on [typeshed](https://github.com/python/typeshed), the repository of types for the standard library and some 3rd party libraries.
  
  https://mypy.readthedocs.io/en/stable/running_mypy.html#missing-library-stubs-or-py-typed-marker
  
  And in fact, `echo > .venv\Lib\site-packages\gitlab\py.typed` fixes the problem for me.