Remove dependency on jQuery

[JD557]

Right now, ScalaDoc depends on jQuery.

From what I can tell, the main reason for it is the table of contents plugin toc.

I would like to suggest replacing jQuery and toc with vanilla JavaScript implementations. While jQuery is still maintained, most of the features are now part of the JavaScript spec, so the migration is not that painful.

On top of that, the current way things are setup doesn't play nicely with JS blockers: Scaladoc works with both JS enabled and disabled, but breaks if JS is enabled only for the page domain (and not for the CDNs)

[SethTisue]

Seems likely a PR on this would be accepted.

[SethTisue]

seems related? #19208

[Math-ias]

I was once again looking for beginner friendly issues to contribute to. I have changes to accomplish just this! Should I create a PR referencing the discussion or does it need to link to an issue first? Here are my changes. https://github.com/Math-ias/scala3-fork/tree/discussion-18903

[sjrd]

Feel free to open a PR.