Python 3.12 removes distutils so it's mandatory to use setuptools with
python >= 3.12.

This patch prints a message when trying to run the setup.py script with
a python >= 3.12 without setuptools and try to use the setuptools import
by default.

This patch also creates a new file, pyproject.toml [1], to prepare for
building in modern systems.

[1] https://peps.python.org/pep-0517/