Bump mkdocs-material from 9.0.12 to 9.0.13

Bumps [mkdocs-material](https://github.com/squidfunk/mkdocs-material) from 9.0.12 to 9.0.13.
- [Release notes](https://github.com/squidfunk/mkdocs-material/releases)
- [Changelog](https://github.com/squidfunk/mkdocs-material/blob/master/CHANGELOG)
- [Commits](squidfunk/mkdocs-material@9.0.12...9.0.13)

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

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

Author: dependabot[bot]

requirements.txt

@@ -1,6 +1,6 @@
 mkdocs==1.4.2
 mkdocs-macros-plugin==0.7.0
-mkdocs-material==9.0.12
+mkdocs-material==9.0.13
 mkdocs-minify-plugin==0.6.2
 mkdocs-git-revision-date-localized-plugin==1.1.0
 mkdocs-snippet-plugin==1.0.2