More CI cleanup, add style workflow

[aliberts]

This does:

• Changes on the test.yml workflow:
  • Using poetry instead of pip. Contrary to what I wrote in CI nightlies cpu/gpu & cleanup #75, it is possible to use poetry (and have the benefits of shorter install times) without the need for having two separate versions of pyproject.toml and poetry.lock.
  • Reduce the trigger scope to only run when files in these directories are modified:
    • lerobot/
    • tests/
    • examples/
    • .github/
• Add style.yml workflow for doing a ruff check pass on the code
• More cleanup (removed deprecated workflow)

[Cadene]

So cool, thank you Simon for converging on a perfect infra workflow ;)

A thought: I am wondering how we could track metrics regarding infra workflow, for instance: install time

[aliberts]

So cool, thank you Simon for converging on a perfect infra workflow ;)

A thought: I am wondering how we could track metrics regarding infra workflow, for instance: install time

Thanks! I will look into it (this looks appealing 👀).
In the meantime, I've just added durations to be printed in test (in 3cc93ab, you can view the result here )

Off the top of my head, it seems that test run times have significantly increased lately and looking at the durations mentioned above, it looks like this is due to the tests added/changed for the examples and datasets. We should maybe review those as well in a future PR to make them faster.