Add Python 3.12 to CI about bdew-datetimes HOT 1 CLOSED

================================================================================ warnings summary ================================================================================
.tox/tests/lib/python3.12/site-packages/dateutil/tz/tz.py:37
  /home/marcel/repositories/bdew-datetimes/.tox/tests/lib/python3.12/site-packages/dateutil/tz/tz.py:37: DeprecationWarning: datetime.datetime.utcfromtimestamp() is deprecated and scheduled for removal in a future version. Use timezone-aware objects to represent datetimes in UTC: datetime.datetime.fromtimestamp(timestamp, datetime.UTC).
    EPOCH = datetime.datetime.utcfromtimestamp(0)

-- Docs: https://docs.pytest.org/en/stable/how-to/capture-warnings.html
========================================================================= 102 passed, 1 warning in 5.26s =========================================================================
  tests: OK (21.34=setup[15.24]+cmd[6.09] seconds)
  congratulations :) (21.82 seconds)