Bump sphinx from 3.4.0 to 3.4.1 in /docs (#571)
Bump sphinx from 3.4.0 to 3.4.1 in /docs (#571)

Bumps [sphinx](https://github.com/sphinx-doc/sphinx) from 3.4.0 to 3.4.1.
- [Release notes](https://github.com/sphinx-doc/sphinx/releases)
- [Changelog](https://github.com/sphinx-doc/sphinx/blob/3.x/CHANGES)
- [Commits](https://github.com/sphinx-doc/sphinx/compare/v3.4.0...v3.4.1)

Signed-off-by: dependabot[bot] <5bdcd3c0d4d24ae3e71b3b452a024c6324c7e4bb@github.com>

Co-authored-by: dependabot[bot] <1c358da00a777d4e9898c1280ab801e2df165188@users.noreply.github.com>
amolenaar/gaphor,amolenaar/gaphor