MNT: (deps): Bump sphinx from 4.1.0 to 4.1.1 in /ci

Bumps [sphinx](https://github.com/sphinx-doc/sphinx) from 4.1.0 to 4.1.1.
- [Release notes](https://github.com/sphinx-doc/sphinx/releases)
- [Changelog](https://github.com/sphinx-doc/sphinx/blob/4.x/CHANGES)
- [Commits](sphinx-doc/sphinx@v4.1.0...v4.1.1)

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

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

ci/doc_requirements.txt

@@ -1,4 +1,4 @@
-sphinx==4.1.0
+sphinx==4.1.1
 # Jinja 3 breaks until we bump pydata-sphinx-theme (I think)
 jinja2<3
 pydata-sphinx-theme==0.5.2