Bump sphinx from 4.1.2 to 4.2.0

Bumps [sphinx](https://github.com/sphinx-doc/sphinx) from 4.1.2 to 4.2.0.
- [Release notes](https://github.com/sphinx-doc/sphinx/releases)
- [Changelog](https://github.com/sphinx-doc/sphinx/blob/4.x/CHANGES)
- [Commits](sphinx-doc/sphinx@v4.1.2...v4.2.0)

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

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

Author: dependabot[bot]

setup.py

@@ -9,7 +9,7 @@
     "docs": [
         "marshmallow>=3.13.0",
         "pyyaml==5.4.1",
-        "sphinx==4.1.2",
+        "sphinx==4.2.0",
         "sphinx-issues==1.2.0",
         "sphinx-rtd-theme==0.5.2",
     ],