Bump mkdocs-material from 8.2.8 to 8.2.9 (#303)

Bumps [mkdocs-material](https://github.com/squidfunk/mkdocs-material) from 8.2.8 to 8.2.9.
- [Release notes](https://github.com/squidfunk/mkdocs-material/releases)
- [Changelog](https://github.com/squidfunk/mkdocs-material/blob/master/CHANGELOG)
- [Commits](squidfunk/mkdocs-material@8.2.8...8.2.9)

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

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

Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

requirements.txt

@@ -5,7 +5,7 @@ MarkupSafe==2.1.1
 mkdocs==1.3.0
 mkdocs-awesome-pages-plugin==2.7.0
 mkdocs-macros-plugin==0.7.0
-mkdocs-material==8.2.8
+mkdocs-material==8.2.9
 mkdocs-simple-hooks==0.1.5
 mkdocstrings==0.18.1
 pip-upgrader==1.4.15