MAINT: Bump sphinx-autobuild from 2021.3.14 to 2024.10.3

Bumps [sphinx-autobuild](https://github.com/sphinx-doc/sphinx-autobuild) from 2021.3.14 to 2024.10.3.
- [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...2024.10.03)

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

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

pyproject.toml

@@ -54,7 +54,7 @@ doc = [
     "numpydoc>=1.5.0,<1.9",
     "Sphinx>=7.1.0,<8.1",
     "sphinx-copybutton>=0.5.0,<0.6",
-    "sphinx-autobuild==2021.3.14; python_version == '3.8'",
+    "sphinx-autobuild==2024.10.3; python_version == '3.8'",
     "sphinx-autobuild==2024.10.3; python_version > '3.8'",
     "nbsphinx>=0.9.0,<0.10",
     "sphinx_design",