Update linters

[martin-martin]

Where to put new files:

• New files should go into a top-level subfolder, named after the article slug. For example: my-awesome-article

How to merge your changes:

1. Make sure the CI code style tests all pass (+ run the automatic code formatter if necessary).
2. Find an RP Team member on Slack and ask them to review & approve your PR.
3. Once the PR has one positive ("approved") review, GitHub lets you merge the PR.
4. 🎉

[martin-martin]

@bzaczynski looks like ruff and/or black changed their rules. Should we run an update formatting pass for a new ground truth? That would introduce some discrepancies with tutorial code, but we have some formatting-related one anyways (e.g. newlines after class definitions).

Or, otherwise, we'd need to make sure our local linters are pinned to the same versions as these ones. Philipp just bumped into this and the CI error messages are somewhat opaque. What do you think? Did you or Geir Arne do such a style update pass previously that you know of?

[bzaczynski]

LGTM!