Bump sphinx from 4.0.3 to 4.1.0 (#5873)

Bumps [sphinx](https://github.com/sphinx-doc/sphinx) from 4.0.3 to 4.1.0.
- [Release notes](https://github.com/sphinx-doc/sphinx/releases)
- [Changelog](https://github.com/sphinx-doc/sphinx/blob/4.x/CHANGES)
- [Commits](sphinx-doc/sphinx@v4.0.3...v4.1.0)

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

Signed-off-by: dependabot[bot] <[email protected]>

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

requirements/doc.txt

@@ -1,6 +1,6 @@
 aiohttp-theme==0.1.6
 pygments==2.9.0
-sphinx==4.0.3
+sphinx==4.1.0
 sphinxcontrib-asyncio==0.3.0
 sphinxcontrib-blockdiag==2.0.0
 towncrier==21.3.0