DOC: Try out sphinx_remove_toctrees
- [ ] closes #54045 (Replace xxxx with the GitHub issue number)
- [ ] [Tests added and passed](https://pandas.pydata.org/pandas-docs/dev/development/contributing_codebase.html#writing-tests) if fixing a bug or adding a new feature
- [ ] All [code checks passed](https://pandas.pydata.org/pandas-docs/dev/development/contributing_codebase.html#pre-commit).
- [ ] Added [type annotations](https://pandas.pydata.org/pandas-docs/dev/development/contributing_codebase.html#type-hints) to new arguments/methods/functions.
- [ ] Added an entry in the latest `doc/source/whatsnew/vX.X.X.rst` file if fixing a bug or adding a new feature.

/preview Website preview of this PR available at: https://pandas.pydata.org/preview/54088/ Thanks for the suggestion @jorisvandenbossche. Looks like the docbuild went from ~1 hour 14 mins to 8 mins! 

It appears the difference is that `Section Navigation` no longer has the collapsible page toctree (as expected), but I think that's okay as it feels redundant with the main content on the page   Not sure if I like this, I am regularly browsing the submenu Can we maybe have them generate on releases only? > Can we maybe have them generate on releases only?

Since the dev docs are released on every push to main, I don't think it's worth the added complexity to only generate them sometimes


Will leave this open for a little bit, but if there is no further support for this I guess I'll close