Add Python 3.12 to the testing

[cclauss]

No description provided.

[jelmer]

The tests seem to be failing due to missing setuptools?

[cclauss]

https://docs.python.org/3/whatsnew/3.12.html

PEP 632: Remove the distutils package. See the migration guide for advice replacing the APIs it provided. The third-party Setuptools package continues to provide distutils, if you still require it in Python 3.12 and beyond.

pyproject.toml: dependencies = ['setuptools ; python_version >= "3.12"']

[cclauss]

Magic ;-)