Bump furo from 2023.5.20 to 2023.9.10 in /docs

Bumps [furo](https://github.com/pradyunsg/furo) from 2023.5.20 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@2023.05.20...2023.09.10)

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

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

Author: dependabot[bot]

docs/requirements.txt

@@ -1,4 +1,4 @@
-furo==2023.5.20
+furo==2023.9.10
 sphinx==7.2.6
 sphinx-click
 myst_parser==2.0.0