DEP(deps): Update sphinx-toolbox requirement from >=4.2.0 to >=4.3.0

Updates the requirements on [sphinx-toolbox](https://github.com/sphinx-toolbox/sphinx-toolbox) to permit the latest version.
- [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@v4.2.0...v4.3.0)

---
updated-dependencies:
- dependency-name: sphinx-toolbox
  dependency-version: 4.3.0
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]

docs/requirements.txt

@@ -15,7 +15,7 @@ jinja2
 sphinxcontrib-napoleon
 
 sphinx-jinja2-compat>=0.4.1
-sphinx-toolbox>=4.2.0
+sphinx-toolbox>=4.3.0
 enum-tools[sphinx]
 pydata-sphinx-theme
 httpx