Bump mkdocs-material from 9.2.6 to 9.2.8

Bumps [mkdocs-material](https://github.com/squidfunk/mkdocs-material) from 9.2.6 to 9.2.8.
- [Release notes](https://github.com/squidfunk/mkdocs-material/releases)
- [Changelog](https://github.com/squidfunk/mkdocs-material/blob/master/CHANGELOG)
- [Commits](squidfunk/mkdocs-material@9.2.6...9.2.8)

---
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]

Docs/requirements.txt

@@ -1,6 +1,6 @@
 mkdocs==1.5.2
 mkdocs-git-revision-date-localized-plugin==1.2.0
 mkdocs-macros-plugin==1.0.4
-mkdocs-material==9.2.6
+mkdocs-material==9.2.8
 mkdocs-section-index==0.3.5
 mkdocstrings[python]==0.22.0