Bump furo from 2023.3.27 to 2023.9.10 in /docs

Bumps [furo](https://github.com/pradyunsg/furo) from 2023.3.27 to 2023.9.10.
- [Release notes](https://github.com/pradyunsg/furo/releases)
- [Changelog](https://github.com/pradyunsg/furo/blob/main/docs/changelog.md)
- [Commits](pradyunsg/furo@2023.03.27...2023.09.10)

---
updated-dependencies:
- dependency-name: furo
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

docs/requirements.txt

@@ -1,3 +1,3 @@
 sphinx==5.3.0
-furo==2023.3.27
+furo==2023.9.10
 myst_parser==1.0.0