Update Sphinx to version 9 #3364
Description
Bumping Sphinx isn't actually going to work, looks like our sphinxcontrib_trio isn't really compatible with Sphinx 9 after they rewrote autodoc. There's an option to use the old code still which would probably make it work temporarily, but we might need to redo that module.
Originally posted by @TeamSpen210 in #3363 (comment)