Bump sphinx from 4.3.2 to 6.1.3 (#76)

Bumps [sphinx](https://github.com/sphinx-doc/sphinx) from 4.3.2 to 6.1.3.
- [Release notes](https://github.com/sphinx-doc/sphinx/releases)
- [Changelog](https://github.com/sphinx-doc/sphinx/blob/master/CHANGES)
- [Commits](sphinx-doc/sphinx@v4.3.2...v6.1.3)

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

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

pyproject.toml

@@ -35,7 +35,7 @@ dev = [
     "usort==1.0.5",
 ]
 docs = [
-    "sphinx==4.3.2",
+    "sphinx==6.1.3",
     "sphinx-mdinclude==0.5.3",
 ]