Bump pymdown-extensions from 9.3 to 9.4

Bumps [pymdown-extensions](https://github.com/facelessuser/pymdown-extensions) from 9.3 to 9.4.
- [Release notes](https://github.com/facelessuser/pymdown-extensions/releases)
- [Commits](https://github.com/facelessuser/pymdown-extensions/compare/9.3...9.4)

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

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

docs/requirements.txt

@@ -9,4 +9,4 @@ mkdocs-minify-plugin==0.5.0
 mkdocs-redirects==1.0.4
 mkdocs==1.3.0
 pygments==2.11.2
-pymdown-extensions==9.3
+pymdown-extensions==9.4