Pin Python 3.11 in pythonpublish workflow

[emontnemery]

The job fails with Python 3.12:

* Creating venv isolated environment...
* Installing packages in isolated environment... (setuptools~=65.6, wheel~=0.37.1)
* Getting build dependencies for sdist...
Traceback (most recent call last):
  File "/opt/hostedtoolcache/Python/3.12.2/x64/lib/python3.12/site-packages/pyproject_hooks/_in_process/_in_process.py", line 353, in <module>
    main()
  File "/opt/hostedtoolcache/Python/3.12.2/x64/lib/python3.12/site-packages/pyproject_hooks/_in_process/_in_process.py", line 335, in main
    json_out['return_val'] = hook(**hook_input['kwargs'])
                             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/opt/hostedtoolcache/Python/3.12.2/x64/lib/python3.12/site-packages/pyproject_hooks/_in_process/_in_process.py", line 281, in get_requires_for_build_sdist
    backend = _build_backend()
              ^^^^^^^^^^^^^^^^
  File "/opt/hostedtoolcache/Python/3.12.2/x64/lib/python3.12/site-packages/pyproject_hooks/_in_process/_in_process.py", line 77, in _build_backend
    obj = import_module(mod_path)
          ^^^^^^^^^^^^^^^^^^^^^^^
  File "/opt/hostedtoolcache/Python/3.12.2/x64/lib/python3.12/importlib/__init__.py", line 90, in import_module
    return _bootstrap._gcd_import(name[level:], package, level)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "<frozen importlib._bootstrap>", line 1387, in _gcd_import
  File "<frozen importlib._bootstrap>", line 1360, in _find_and_load
  File "<frozen importlib._bootstrap>", line 1310, in _find_and_load_unlocked
  File "<frozen importlib._bootstrap>", line 488, in _call_with_frames_removed
  File "<frozen importlib._bootstrap>", line 1387, in _gcd_import
  File "<frozen importlib._bootstrap>", line 1360, in _find_and_load
  File "<frozen importlib._bootstrap>", line 1331, in _find_and_load_unlocked
  File "<frozen importlib._bootstrap>", line 935, in _load_unlocked
  File "<frozen importlib._bootstrap_external>", line 995, in exec_module
  File "<frozen importlib._bootstrap>", line 488, in _call_with_frames_removed
  File "/tmp/build-env-3s2nezir/lib/python3.12/site-packages/setuptools/__init__.py", line [16](https://github.com/home-assistant-libs/pychromecast/actions/runs/7914157028/job/21603312868#step:5:17), in <module>
    import setuptools.version
  File "/tmp/build-env-3s2nezir/lib/python3.12/site-packages/setuptools/version.py", line 1, in <module>
    import pkg_resources
  File "/tmp/build-env-3s2nezir/lib/python3.12/site-packages/pkg_resources/__init__.py", line 2[19](https://github.com/home-assistant-libs/pychromecast/actions/runs/7914157028/job/21603312868#step:5:20)1, in <module>
    register_finder(pkgutil.ImpImporter, find_on_path)
                    ^^^^^^^^^^^^^^^^^^^
AttributeError: module 'pkgutil' has no attribute 'ImpImporter'. Did you mean: 'zipimporter'?

ERROR Backend subprocess exited when trying to invoke get_requires_for_build_sdist