[2.11..2.13] Grep away deprecation warning for distutils

... which will be removed in Python 3.12, and that probably won't be used on systems running the AppArmor 2.1x branches.

This prevents CI failures on gitlab.com, which uses a new-enough python to show

DeprecationWarning: The distutils package is deprecated and slated for removal in Python 3.12. Use setuptools or check PEP 632 for potential alternatives

For 3.0 and master, the proper fix (switching to setuptools) was done in !813 (merged).

I propose this patch for 2.11, 2.12 and 2.13.