Bump sphinx-autobuild from 2021.3.14 to 2024.9.17

Bumps [sphinx-autobuild](https://github.com/sphinx-doc/sphinx-autobuild) from 2021.3.14 to 2024.9.17.
- [Release notes](https://github.com/sphinx-doc/sphinx-autobuild/releases)
- [Changelog](https://github.com/sphinx-doc/sphinx-autobuild/blob/main/NEWS.rst)
- [Commits](sphinx-doc/sphinx-autobuild@2021.03.14...2024.09.17)

---
updated-dependencies:
- dependency-name: sphinx-autobuild
  dependency-type: direct:production
  update-type: version-update:semver-major
...

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

requirements/docs.txt

@@ -1,7 +1,7 @@
 -r main.txt
 furo==2024.5.6
 Sphinx>4,<8
-sphinx-autobuild==2021.3.14
+sphinx-autobuild==2024.9.17
 sphinx-copybutton==0.5.2
 sphinx-inline-tabs==2023.4.21
 sphinx-issues==4.1.0