Perform some tests with Python Multithreading without GIL

[antoinecarme]

As of 2021, CPython implementation still uses the infamous "global interpreter lock (GIL)".

This is the design point behind PyAF using the multiprocessing module and not multithreading.

Now, there is a POC to remove the GIL for CPython (thanks to @colesbury ):

https://github.com/colesbury/nogil

The goal of this issue is to perform some initial tests with nogil and PyAF.

Not sure if this will help with the upcoming PyAF release (Probably later).

[antoinecarme]

Pre-built Docker image (Python 3.9 , Debian BullsEye):

https://hub.docker.com/r/colesbury/python-nogil