[Python] Deprecate distutils for setuptools when possible

In CPython 3.10 distutils was formally marked as deprecated and it will be
removed from CPython in 3.12. To avoid complications, deprecate use of distutils
moving forward in favor of using setuptools as recommended.

For Python 3.7+ (which should by default have pip v22.0.0+ and
setuptools v57.5.0+) use:
* `setuptools._distutils.core` over `distutils.core`
* CPython's sysconfig library over `distutils.sysconfig`

If `setuptools._distutils` (added in setuptools v48.0.0) is not available
in the Python 3 environment, fall back to using `distutils.core` and
`distutils.sysconfig`.

For Python < 3.7 (so Python 3.6 only for all intents and purposes) there
is an upper limit on setuptools versions that will work with sysconfig of
setuptools v47.3.2 given how setup.py.in is currently written. To avoid
problems, fall back to distutils.sysconfig in the event that setuptools
is v48.0.0+.

Additional supporting advice given in:
* https://setuptools.pypa.io/en/latest/deprecated/distutils-legacy.html
* https://peps.python.org/pep-0632/#migration-advice

bindings/python/setup.py.in

@@ -1,7 +1,23 @@
 from __future__ import print_function
 
-from distutils.core import setup, Extension
-from distutils import sysconfig
+# setuptools._distutils added in setuptools v48.0.0
+# c.f. https://setuptools.pypa.io/en/latest/history.html#v48-0-0
+try:
+    from setuptools._distutils.core import setup, Extension
+    # sysconfig v48.0.0+ is incompatible for Python 3.6 only, so fall back to distutils.
+    # Instead of checking setuptools.__version__ explicitly, use the knowledge that
+    # to get here in the 'try' block requires setuptools v48.0.0+.
+    # FIXME: When support for Python 3.6 is dropped simplify this
+    import sys
+
+    if sys.version_info < (3, 7):
+        from distutils import sysconfig
+    else:
+        import sysconfig
+except ImportError:
+    from distutils.core import setup, Extension
+    from distutils import sysconfig
+
 from os import getenv, walk, path
 import subprocess