Test without Qt installed
Once #22 is done, it may also be worthwhile adding a test that doesn't install and Qt bindings to confirm that it is possible to run all non-GUI-tests without having a Qt binding installed. (This is also a way to keep the code "clean", not mixing GUI and non-GUI functionality.)
https://docs.pytest.org/en/7.1.x/how-to/skipping.html#skipping-on-a-missing-import-dependency