Bump mkdocs-material from 8.1.9 to 8.1.11 (#272)

Bumps [mkdocs-material](https://github.com/squidfunk/mkdocs-material) from 8.1.9 to 8.1.11.
- [Release notes](https://github.com/squidfunk/mkdocs-material/releases)
- [Changelog](https://github.com/squidfunk/mkdocs-material/blob/master/CHANGELOG)
- [Commits](squidfunk/mkdocs-material@8.1.9...8.1.11)

---
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

@@ -2,7 +2,7 @@ click==8.0.3
 flake8==4.0.1
 mkdocs-awesome-pages-plugin==2.6.1
 mkdocs-macros-plugin==0.6.4
-mkdocs-material==8.1.9
+mkdocs-material==8.1.11
 mkdocs==1.2.3
 mkdocstrings==0.17.0
 pip-upgrader==1.4.15