Bump mkdocs-material from 8.5.7 to 8.5.9

Bumps [mkdocs-material](https://github.com/squidfunk/mkdocs-material) from 8.5.7 to 8.5.9.
- [Release notes](https://github.com/squidfunk/mkdocs-material/releases)
- [Changelog](https://github.com/squidfunk/mkdocs-material/blob/master/CHANGELOG)
- [Commits](squidfunk/mkdocs-material@8.5.7...8.5.9)

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

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

requirements.txt

@@ -7,7 +7,7 @@ mkdocs==1.4.1
 mkdocs-awesome-pages-plugin==2.8.0
 mkdocs-click==0.8.0
 mkdocs-macros-plugin==0.7.0
-mkdocs-material==8.5.7
+mkdocs-material==8.5.9
 mkdocstrings==0.19.0
 mkdocstrings-python-legacy==0.2.3
 pip-upgrader==1.4.15