Instant search results are broken

[YuriSizov]

Your Godot version:
Any.

Issue description:
Instant search popup started to generate broken search results today. It appends .html extension twice, making links invalid.

This is probably related to readthedocs/readthedocs.org#7070 and readthedocs/readthedocs-sphinx-search#50.

I guess something RTD related must be updated? Also, we probably shouldn't depend on master tip in case of sphinx-search despite their recommendation to do so.

URL to the documentation page:
Example of a link: https://docs.godotengine.org/en/stable/classes/class_editorsettings.html.html

[akien-mga]

It seems to work fine on latest, I think a rebuild of stable and 3.2 will fix it.

[YuriSizov]

Search seems to be working fine now on stable and 3.2, and #3567 addresses the second part.