Bump sphinx from 4.3.0 to 4.3.1

Bumps [sphinx](https://github.com/sphinx-doc/sphinx) from 4.3.0 to 4.3.1.
- [Release notes](https://github.com/sphinx-doc/sphinx/releases)
- [Changelog](https://github.com/sphinx-doc/sphinx/blob/4.x/CHANGES)
- [Commits](sphinx-doc/sphinx@v4.3.0...v4.3.1)

---
updated-dependencies:
- dependency-name: sphinx
  dependency-type: direct:development
  update-type: version-update:semver-patch
...

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

Author: dependabot[bot]

poetry.lock

@@ -35,7 +35,7 @@ pytest = "^6.2.5"
 pytest-cov = "^3.0.0"
 pytest-mock = "^3.6.1"
 tox = "^3.24.4"
-Sphinx = "^4.3.0"
+Sphinx = "^4.3.1"
 
 [build-system]
 requires = ["poetry_core>=1.0.0"]