Make nav run on python3.11

[hmpf]

In order to run on debian bookworm, we need to support running on python 3.11. See #2718.

• Upgrade to Django 4.2 #2789
• Get rid of libsass (We need to replace libsass #2719)
• Upgrade Twisted to a version that supports Python 3.11 #2792
• Upgrade psycopg to 2.9 #2793
• Get rid of crispy-forms #2794
• Replace all uses of pkg_resources with importlib #2791
• Upgrade to tox 4 #2973
  • See also [BUG] "tox -e docs" fails #2714, Nav cannot be built with python 3.11 #2718
• Replace Foundation javascript #2972