Bump sphinxext-opengraph from 0.8.2 to 0.9.1

Bumps [sphinxext-opengraph](https://github.com/wpilibsuite/sphinxext-opengraph) from 0.8.2 to 0.9.1.
- [Release notes](https://github.com/wpilibsuite/sphinxext-opengraph/releases)
- [Commits](wpilibsuite/sphinxext-opengraph@v0.8.2...v0.9.1)

---
updated-dependencies:
- dependency-name: sphinxext-opengraph
  dependency-type: direct:development
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <[email protected]>