Flask / Werkzeug 3.0 and Python 3.12 updates

[nickjj]

These are updates I'd like to perform but there's currently a few blockers from 3rd party dependencies:

• [Flask 3.0] https://github.com/pallets-eco/flask-debugtoolbar needs a new release so fix: use urllib.parse.quote_plus and drop werkzeug.urls.url_quote_plus pallets-eco/flask-debugtoolbar#207 is included
• [Flask 3.0] https://github.com/maxcountryman/flask-login needs a new release so flask 3.0 compatibility maxcountryman/flask-login#778 is included
  • This package is one of the most popular 3rd party packages for handling user authentication, I think it's important that this project remains compatible with Flask-Login even though it's not using it out of the box
• [Python 3.12] Kombu may rely on locking in functools.cached_property that will be removed in Python 3.12 celery/kombu#1668 will need to be addressed and available in a new release

If anyone is using other popular 3rd party libraries that aren't working with either Flask 3.0 or Python 3.12 please post them here.

[nickjj]

Flask-Login shipped v0.6.3 which has Flask 3.0 compatibility. I adjusted this original issue to turn each bullet into a todo item.

[nickjj]

Flask-Debugtoolbar shipped v0.14.1 which has Flask 3.0 compatibility.

This gives us the green light to use Flask 3.0 which has now been pushed to the main branch.

[nickjj]

While that Kombu issue didn't get fixed, you can adjust how Celery is initialized to make it work with Python 3.12. That's been pushed here: 21189ac

That completes all of the tasks here, we're back to being fully up to date!