Fix sphinx linking issue

[kandersolar]

• [ ] Closes #xxxx
• I am familiar with the contributing guidelines
• [ ] I attest that all AI-generated material has been vetted for accuracy and is in compliance with the pvlib license no AI
• [ ] 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.
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In #2863, I accidentally broke the bifacial reference page. This PR fixes it.

Caught by @echedey-ls here: #2863 (comment)

[echedey-ls]

LGTM, docs are good now. Thanks @kandersolar !