Build: Bump mkdocs-material-extensions from 1.3 to 1.3.1

Bumps [mkdocs-material-extensions](https://github.com/facelessuser/mkdocs-material-extensions) from 1.3 to 1.3.1.
- [Release notes](https://github.com/facelessuser/mkdocs-material-extensions/releases)
- [Changelog](https://github.com/facelessuser/mkdocs-material-extensions/blob/master/changelog.md)
- [Commits](facelessuser/mkdocs-material-extensions@1.3...1.3.1)

---
updated-dependencies:
- dependency-name: mkdocs-material-extensions
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

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

mkdocs/requirements.txt

@@ -24,5 +24,5 @@ mkdocs-literate-nav==0.6.1
 mkdocs-autorefs==0.5.0
 mkdocs-gen-files==0.5.0
 mkdocs-material==9.4.8
-mkdocs-material-extensions==1.3
+mkdocs-material-extensions==1.3.1
 mkdocs-section-index==0.3.8