Bump sphinx-substitution-extensions from 2024.2.25 to 2024.8.6

Bumps [sphinx-substitution-extensions](https://github.com/adamtheturtle/sphinx-substitution-extensions) from 2024.2.25 to 2024.8.6.
- [Release notes](https://github.com/adamtheturtle/sphinx-substitution-extensions/releases)
- [Changelog](https://github.com/adamtheturtle/sphinx-substitution-extensions/blob/main/CHANGELOG.rst)
- [Commits](adamtheturtle/sphinx-substitution-extensions@2024.02.25...2024.08.06)

---
updated-dependencies:
- dependency-name: sphinx-substitution-extensions
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

Author: dependabot[bot]

pyproject.toml

@@ -60,7 +60,7 @@ optional-dependencies.dev = [
     "ruff==0.5.6",
     "sphinx==7.4.7",
     "sphinx-copybutton==0.5.2",
-    "sphinx-substitution-extensions==2024.2.25",
+    "sphinx-substitution-extensions==2024.8.6",
     "sphinxcontrib-spelling==8",
     "sybil==6.1.1",
     "types-requests==2.32.0.20240712",