Update minimal python version

[rvhonorato]

Desired feature/enhancement

Update minimal python version to a recent release

Motivation

Currently the recomended python version is 3.9, which is already a quite old version and it's marked as legacy and it's end-of-life is due 2025. Here we should be using the most recent version - 3.12

Description

Developing code based on an old python interpreter might cause plenty of issues as the new code can use features that are deprecated in newest versions, as well as blocks in the dependencies.

Additional context

The "simplest" way to do this update is to try to install and run the tests on 3.12 and see what are the incompatibilities.