Keep object entries in TOC in short form #34710
Description
Sphinx, upgraded to 5.2.3 in #34615, builds the doc with object (classes, functions, ...) entries in toc (table of contents).
We keep the object entries in TOC, but remove them from the main index pages.
CC: @kiwifb @fchapoton @tscrim @mkoeppe @dimpase
Component: documentation
Author: Kwankyu Lee
Branch/Commit: a1b70f3
Reviewer: François Bissey
Issue created by migration from https://trac.sagemath.org/ticket/34710