More testing

[github-actions[bot]]

:point_left: Try it on ReadTheDocs

[jtpio]

Maybe we could start looking into adding Playwright tests as well at some point.

[martinRenou]

Yes that could be good

[martinRenou]

Or I'd rather like an equivalent of jupyter kernel test but using pyjs code runner, that way we really test the kernel features itself, not the rendering

[jtpio]

Right. Although there might be some issues related to the in-browser kernel not being able to start correctly when running in an actual browser, which could be caught by the end-to-end checks.