[DOC] Tooltips are always shown in light mode, even in dark mode.

[echedey-ls]

I know some people that would argue that's a health issue (me).

• Closes Dark mode for hoverxref tooltips #2346
• I am familiar with the contributing guidelines
• [ ] Tests added
• [ ] Updates entries in docs/sphinx/source/reference for API changes.
• [ ] Adds description and name entries in the appropriate "what's new" file in docs/sphinx/source/whatsnew for all changes. Includes link to the GitHub Issue with :issue:`num` or this Pull Request with :pull:`num`. Includes contributor name and/or GitHub username (link with :ghuser:`user`).
• New code is fully documented. Includes numpydoc compliant docstrings, examples, and comments where necessary.
• Pull request is nearly complete and ready for detailed review.
• Maintainer: Appropriate GitHub Labels (including remote-data) and Milestone are assigned to the Pull Request and linked Issue.
• Links to the relevant documentation pages cause you think about the other maintainers: https://pvlib-python--2348.org.readthedocs.build/en/2348/

[RDaxini]

funny branch name 😂

[wholmgren]

Have we considered fixing this upstream instead of in pvlib?

[echedey-ls]

Have we considered fixing this upstream instead of in pvlib?

That would be nuts, although it does not seem easy since each theme (e.g. pydata-sphinx-theme) provides it's own way of specifying the theme colours (source comment). Anyways, they would surely welcome any PR in that regard. I wouldn't be able to do so, thou. So I propose mitigating this problem now this easy way and removing these changes in the future once it gets fixed (if so).