Python: replace deprecated 'distutils'

[alalek]

Python 3.10 starts emit warnings from OpenCVDetectPython.cmake detection script:

<string>:1: DeprecationWarning: The distutils package is deprecated and slated for removal in Python 3.12. Use setuptools or check PEP 632 for potential alternatives
<string>:1: DeprecationWarning: The distutils.sysconfig module is deprecated, use sysconfig instead