Revert CORS tests from "[LAB-20] Update tests, also some fixes"
Revert CORS tests from "[LAB-20] Update tests, also some fixes"

I removed the CORS header stuff from this branch as it was causing
trouble, forgot to remove its tests (somehow)

Leaving in history as a revert commit so I can resurrect it later if we
want.

brandonivey/django-marimo,brandonivey/django-marimo