Update furo requirement from ~=2023.9.10 to ~=2024.1.29

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@2023.09.10...2024.01.29)

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

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

docs/requirements.txt

@@ -1,3 +1,3 @@
 sphinx<8
-furo~=2023.9.10
+furo~=2024.1.29
 sphinx-copybutton~=0.5