[Bug]: DeprecationWarning for pkg_resources.declare_namespace usage in mpl_toolkit #25244
Description
Bug summary
As of setuptools v67.3.0 the use of pkg_resources.declare_namespace in lib/mpl_toolkits/__init__.py raises a DeprecationWarning.
Code for reproduction
$ mamba create -n test python=3.10 matplotlib-base -y
$ mamba activate test
$ export PYTHONDEVMODE=1
$ python -c "import pkg_resources"Actual outcome
/path/to/test/lib/python3.10/site-packages/pkg_resources/__init__.py:2804: DeprecationWarning: Deprecated call to `pkg_resources.declare_namespace('mpl_toolkits')`.
Implementing implicit namespace packages (as specified in PEP 420) is preferred to `pkg_resources.declare_namespace`. See https://setuptools.pypa.io/en/latest/references/keywords.html#keyword-namespace-packages
declare_namespace(pkg)
Expected outcome
No output
Additional information
See also:
https://setuptools.pypa.io/en/latest/references/keywords.html#keyword-namespace-packages
https://packaging.python.org/en/latest/guides/packaging-namespace-packages/
https://peps.python.org/pep-0420/
Operating system
No response
Matplotlib Version
3.7.0
Matplotlib Backend
TkAgg
Python version
Python 3.10.9
Jupyter version
No response
Installation
conda