Fix CI and test with python 3.13

[aabmass]

This fixes failing CI checks.

• Pinning ubuntu to 22.04 so that python 3.7 is still available (Version 3.7 was not found in the local cache actions/setup-python#962). We should eventually drop 3.7 (Drop python 3.7 support which is EOL, add 3.13 #367), which is EOL.
• Start testing python 3.13 while we're at it