1.2.14: SetuptoolsDeprecationWarning due to the use of `sys.exit(0)`

[dvzrv]

Hi! 👋

I package this project for Arch Linux.

During update to 1.2.14 I noticed that setuptools now raises the following warning:

/usr/lib/python3.13/site-packages/setuptools/build_meta.py:522: SetuptoolsDeprecationWarning: Running `setup.py` directly as CLI tool is deprecated.
!!

        ********************************************************************************
        Please avoid using `sys.exit(0)` or similar statements that don't fit in the paradigm of a configuration file.

        See https://blog.ganssle.io/articles/2021/10/setup-py-deprecated.html for details.
        ********************************************************************************

!!
  super().run_setup(setup_script=setup_script)

This appears to be triggered by the sys.exit(0) call in setup.py:

alsa-python/setup.py

Lines 74 to 75 in 20b2b39

	if sys.argv[1] != 'build':
	sys.exit(0)

(Setuptools now offers one of the various PEP517 build backends and calling setup.py directly as a script is deprecated).

Looking at the file I noticed that there are still conditionals that accommodate Python2:

alsa-python/setup.py

Lines 77 to 80 in 20b2b39

	if sys.version_info < (3, 0):
	dir = 'build/lib.%s-%s-%s/pyalsa' % (uname[0].lower(), uname[4], sys.version[:3])
	else:
	dir = 'build/lib.%s-%s-cpython-%s%s/pyalsa' % (uname[0].lower(), uname[4], sys.version_info.major, sys.version_info.minor)

Those should be removed, as the script itself is marked as Python3 (and well of course because Python2 is long discontinued 😅).