scons,stdlib: Remove deprecated 'distutils' module

The Python module 'distutils' will be removed in Python 3.12:
https://docs.python.org/3/library/distutils.html

This patch removed usage of 'distutils' in the gem5 code base.

Change-Id: I1e3a944446149f3cd6cbf4211a1565b5f74c85a0
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/71679
Tested-by: kokoro <noreply+kokoro@google.com>
Maintainer: Jason Lowe-Power <power.jg@gmail.com>
Reviewed-by: Jason Lowe-Power <power.jg@gmail.com>