Update sphinx requirement from ~4.5 to ~6.2 (#20)

Updates the requirements on [sphinx](https://github.com/sphinx-doc/sphinx) to permit the latest version.
- [Release notes](https://github.com/sphinx-doc/sphinx/releases)
- [Changelog](https://github.com/sphinx-doc/sphinx/blob/master/CHANGES)
- [Commits](sphinx-doc/sphinx@v4.5.0...v6.2.1)

---
updated-dependencies:
- dependency-name: sphinx
  dependency-type: direct:development
...

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

Author: dependabot[bot]

pyproject.toml

@@ -34,7 +34,7 @@ pytest-asyncio = "~0.21"
 pytest-cov = "~4.1"
 pytest-unordered = "~0.5"
 pre-commit = "~3.3"
-Sphinx = "~4.5"
+Sphinx = "~6.2"
 sphinx-rtd-theme = "~1.2"
 sphinxcontrib-napoleon = "~0.7"
 m2r = "~0.3"