Tests and Monthly Automated Tag

[dario-coscia]

Describe the bug In the testing_pr.yml file the tests are run for python 3.8, 3.9, 3.10, 3.11, 3.12.

In the monthly-tag.yml only 3.7 and 3.8 are tested.

While in the ReadMe compatibility is ensured for 3.7,3.8, 3.9, 3.10.

Expected behavior I expect PINA to run for python 3.8, 3.9, 3.10, 3.11, 3.12 so the ReadMe and the monthly-tag.yml should be changed accordingly.

[dario-coscia]

Also consider to update the PyPl page for Python >= 3.8