docs: bump furo from 2024.4.27 to 2024.5.6 in /docs

Bumps [furo](https://github.com/pradyunsg/furo) from 2024.4.27 to 2024.5.6.
- [Release notes](https://github.com/pradyunsg/furo/releases)
- [Changelog](https://github.com/pradyunsg/furo/blob/main/docs/changelog.md)
- [Commits](pradyunsg/furo@2024.04.27...2024.05.06)

---
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

@@ -1,2 +1,2 @@
-furo==2024.4.27
+furo==2024.5.6
 sphinx==7.3.7