-r doc.txt
sphinxcontrib-spelling==5.0.0; platform_system!="Windows"  # We only use it in Travis CI

-r doc.txt
sphinxcontrib-spelling==5.1.0; platform_system!="Windows"  # We only use it in Travis CI

Bump sphinxcontrib-spelling from 5.0.0 to 5.1.0
Build(deps): Bump sphinxcontrib-spelling from 5.0.0 to 5.1.0

Bumps [sphinxcontrib-spelling](https://github.com/sphinx-contrib/spelling) from 5.0.0 to 5.1.0.
- [Release notes](https://github.com/sphinx-contrib/spelling/releases)
- [Commits](https://github.com/sphinx-contrib/spelling/compare/5.0.0...5.1.0)

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