Python 3.11 module

This MR adds a tools/python/3.11 module that installs a non-invasive Python 3.11 executable (python-3.11) into <ws>/.axii/bin.

This can be used to create venvs with other Python versions, for example in Axii:

python-3.11 -m venv .venv-3.11
source .venv-3.11/bin/activate
pip install --upgrade pip
pip install -r requirements/development.txt

Thanks to @meixner for helping out.