Test python 3.12

As per 2025.1 testing runtime, Python 3.12 is the
max python version to test. Adding the test job
as well update the document to support it.

Also, remove the python_requires flag from setup.cfg
which stop installing it on python version lower
than the min supported. Let's allow to install and as
long as it work for older python it is ok. User can
get to know the supported python versions from
classifier also.

Change-Id: Ibd4ad33bdc30512568843358973c716b21d039de
3 files changed