[WIP] Django 4.2 upgrade

[saechtner]

Details

• Upgrade django to 4.2
• Removed explicit sqlparse dependency because it's implicit in django 2.2+
• Removed django admin because it wasn't used and broke
• Removed debug toolbar because it (hopefully) wasn't used and broke
• Upgrade bootstrap3 to 23.1
• Fixed moved django url imports
• Explicit on_delete definition for all foreign keys as required. Kept current default behavior of on_delete=models.CASCADE.
• Defined app_label for all models as required
• Replaced {% load staticfiles %} template tag with {% load static %} as required
• Ran https://github.com/adamchainz/django-upgrade via precommit to fix v3 url definitions and translation imports
• Ran limited pre-commit to avoid too many distracting changes but a couple snuck in anyways

Known issues

• Possibly drag and drop issue in assign athletes when dropping athletes. Clicking to assign still functional. https://github.com/saechtner/turn-events/issues/21

[naechtner]

Localization has been fixed in c757ad1daace18264c0f4b5208205000fd845f06. Some middlewares had to be removed (none of them were actually installed anyways since django2.2). We should check what happened to the sessionauthentication middleware. But everything appears to work now in terms of localization.