[CONTENT] Update babel

[Felienne]

We keep adding languages that our Babel version does not support (today: Papiamentu) which exist in Weblate but not in babel:

We are running old versions of babel, maybe updating it will add some new locales?

We run 2.11 but Babel is at 2.13.1: https://babel.pocoo.org/en/latest/changelog.html#version-2-13-1

And Flask-babel is at 4.0.0 now: https://python-babel.github.io/flask-babel/ (not the cause of this problem but we are very far behind, maybe we should update that too?)

If the problem is solved, we can remove these overrides:

f5df62d

[Felienne]

If Babel has a new release, tn and pap should be supported (thanks to @rix0rrr!! -> python-babel/babel#1043) 🥳

So we should keep an eye on a new release, update and remove our patch code:
https://github.com/python-babel/babel/releases/tag/v2.13.1