Remove dependence on jquery

[choldgraf]

Context

Sphinx 6.0 is going to remove the jquery dependency by default. We use jquery a little bit in this theme, though likely not in a way that strictly requires jquery.

Here's a GitHub CS search for the $( symbol

Note that our parent theme removed JQuery as a dependency here:

• MAINT: Drop jQuery and use Bootstrap 5 pydata/pydata-sphinx-theme#1029

Proposal

We should remove all of our code that depends on JQuery, and only manually add the JQuery dependency if we really need it.

Tasks and updates

• Remove instances of $( in the theme as well as JQuery notes anywhere
• Remove tooltip functionality and popper.js
• Remove the styling of div.tooltip since we no longer use Bootstrap for this
• Double-check functionality is the same