Hidden toctree still generates a toctree-wrapper div in output html

[alexisthual]

Describe the bug

Currently, sphinx generates a <div class="toctree-wrapper compound"> </div> even when toctree is :hidden:.
I think it'd be more consistent if nothing was added to the DOM when toctree is hidden.

My guess is that it boils down to changing this part of the code

sphinx/sphinx/directives/other.py

Lines 79 to 85 in f38bd8e

	wrappernode = nodes.compound(classes=['toctree-wrapper'])
	wrappernode.append(subnode)
	self.add_name(wrappernode)
	ret = self.parse_content(subnode)
	ret.append(wrappernode)
	return ret

and maybe only run ret.append(wrappernode) when subnode['hidden'] is not False?

Let me know what you think!

How to Reproduce

$ git clone https://github.com/.../some_project
$ cd some_project
$ pip install -r requirements.txt
$ cd docs
$ make html SPHINXOPTS="-D language=de"
$ # open _build/html/index and see bla bla

Expected behavior

No response

Your project

https://github.com/nilearn/nilearn

Screenshots

No response

OS

Ubuntu

Python version

3.9

Sphinx version

4.3.2

Sphinx extensions

No response

Extra tools

No response

Additional context

No response