Test "builds" for different Python main versions
Summary
Timor officially supports Python 3.7, 3.8, 3.9, 3.10 - but it's currently not tested whether the pip installation and local installation works for all of these.
What should be done
Add build tests to the CI.
Relevant logs and/or screenshots
This issue has been brought up in a previous discussion: !13 (comment 2037172)