Avoid using deprecated distutils module

[slyon]

The distutils module has been deprecated since python 3.10 and leads to deprecation warnings during the test of gnome-gmail. Which leads to failed tests (due to output/deprecation warnings on stderr) in Ubuntu 22.04. PEP 632 suggests using the setuptools module instead: https://www.python.org/dev/peps/pep-0632/#migration-advice

# python3 setup.py test --pytest-args --ignore=test/test_setup.py
/tmp/autopkgtest.c1v6yk/build.RDc/src/setup.py:3: DeprecationWarning: The distutils package is deprecated and slated for removal in Python 3.12. Use setuptools or check PEP 632 for potential alternatives
  from distutils.core import setup, Command
running test
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