ensure compatibility with numpy 2.0

[raphaelvallat]

See the NumPy 2.0 migration guide

[remrama]

It's probably straightforward to run Ruff's rule once on the pingouin code to conform to Numpy 2.0. But @raphaelvallat are you cool with simultanously replacing both Black and Flake8 with Ruff? It should be configurable within pyproject.toml to match the current rules of both. They also offer a drop-in GitHub Action workflow that could replace pingouin's current Black Action. I've implemented this before on a recent project and found it a convenient one-stop solution for these things.

[raphaelvallat]

Yeah, I keep hearing good things about ruff so let's change

[remrama]

Adding a checklist for this Issue that combines goals of numpy 2.0 compatibility with ruff replacement.

• Replace black with ruff in pyproject.toml
• Replace flake8 with ruff in pyproject.toml
• Replace black GitHub Action with ruff GitHub action
• Run ruff's formatter (in case of minor deviations from black)
• Run ruff's linter (in case of minor deviations from flake8)
• Run ruff's numpy 2.0 compatibility enforcer
• Replace black and flake8 with ruff in Contributing sections in docs and README.

[remrama]

@raphaelvallat this got addressed when #446 was merged, so you can close it as completed 👍 ✅