- Does not upgrade other dependencies, might not actually work in
  isolation

- Django 4.0 changes the default timezone implementation to be zoneinfo
  from the standard library, instead of pytz, we can therefore remove it
  as a direct dependency.

- Use npm instead of yarn 1, I don't have a strong opinion here and can
  split it out/revert it
- This removes a lot of the DX for building the frontend locally, but
  noone has used than in a long while, and it is a lot less work to
  remove it than figure out how to get it properly working at this
  point.
- This probably requires additional changes before prod deploy works,
  and upgrades linting, but does not change any code to make it pass CI

- 'Urls' is just a global variable injected through Django-templates,
  there is a js-library we could use, but that would have be bad for
  performance since you have to request a .json file at runtime, and
  probably use async, which is a lot of code-changes.

- Esbuild is less config and dependencies than webpack, this does lose
some hot-reloading abilities, but that should be mitigated by using
--watch, and esbuild is wildly more performant than webpack
- Ideally we would yeet `less` for plain css, but that is a bit more
  work for now.
- We now consequently use LTS node 18
- The usage of `~` is imports in `less` appears to be deprecated (?),
  they had to be changed for esbuild to work at least.
- Creating the webpack-stats.json-build from esbuild's `meta.json` is
  kinda wacky, we could also just for django-webpack-loader to support
  `meta.json`, the whole frontend-setup is strange anyways.

- It should only be added if `--no-optional` is used in prod, which it
  isn't