Tests fail with default install because of Django 5

[GlennS]

If you run the following in a fresh clone of xocto, it will break:

python 3 -m venv ../venv-xocto 
. ../venv-xocto/bin/activate 
make install 
make test

Two reasons for this, both related to it installing Django 5 (presumably xocto has only been tested against Django 4, and a new release has broken this for us):

These filters in our pyproject.toml
Something about timezones

Internal ticket