Upgrade to python 3.11

[JasonGrace2282]

Python 3.7 has been EOL for a year now, and Python 3.8 is EOL in October. It's time for a bump to 3.11.

[!WARNING]
This will require an Ubuntu update as well, once this PR is ready to be reviewed/merged.

I tried to keep the commits organized, with

• Pipfile updates
• Automated fixes (mostly typehints+f-strings) EDIT: diff was large, so I decided to move it to a follow-up PR.
• Manual Changes (if any)

[!NOTE] This PR should speed up director a little bit as well, see https://docs.python.org/3/whatsnew/3.11.html#whatsnew311-faster-cpython

[JasonGrace2282]

I've hit a roadblock with the django-stubs plugin that should (from my testing) be solved by #81. Until then, there isn't really much I can do.