build(deps): bump sphinx-toolbox from 3.10.0 to 4.0.0 in /requirements (#20836)

Bumps [sphinx-toolbox](https://github.com/sphinx-toolbox/sphinx-toolbox) from 3.10.0 to 4.0.0.
- [Release notes](https://github.com/sphinx-toolbox/sphinx-toolbox/releases)
- [Changelog](https://github.com/sphinx-toolbox/sphinx-toolbox/blob/master/doc-source/changelog.rst)
- [Commits](sphinx-toolbox/sphinx-toolbox@v3.10.0...v4.0.0)

---
updated-dependencies:
- dependency-name: sphinx-toolbox
  dependency-version: 4.0.0
  dependency-type: direct:production
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <[email protected]>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Author: dependabot[bot]

requirements/docs.txt

@@ -12,7 +12,7 @@ sphinx-paramlinks >=0.5.1, <=0.6.0
 sphinx-togglebutton >=0.2, <=0.3.2
 sphinx-copybutton >=0.3, <=0.5.2
 sphinx-multiproject
-sphinx-toolbox ==3.10.0
+sphinx-toolbox ==4.0.0
 sphinx-rtd-dark-mode
 sphinxcontrib-video ==0.4.1
 jinja2 <3.2.0