🤖 Update furo requirement

Updates the requirements on [furo](https://github.com/pradyunsg/furo) to permit the latest version.
- [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...2024.08.06)

---
updated-dependencies:
- dependency-name: furo
  dependency-type: direct:production
...

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

requirements/docs.txt

@@ -1,5 +1,5 @@
 sphinx<9
-furo>=2024.4.27,<2024.8
+furo>=2024.4.27,<2024.9
 sphinx-copybutton~=0.5
 myst-parser>=3,<5
 enum-tools[sphinx]==0.12.0