Bump mkdocs-material from 9.6.17 to 9.6.18

Bumps [mkdocs-material](https://github.com/squidfunk/mkdocs-material) from 9.6.17 to 9.6.18.
- [Release notes](https://github.com/squidfunk/mkdocs-material/releases)
- [Changelog](https://github.com/squidfunk/mkdocs-material/blob/master/CHANGELOG)
- [Commits](https://github.com/squidfunk/mkdocs-material/compare/9.6.17...9.6.18)

---
updated-dependencies:
- dependency-name: mkdocs-material
  dependency-version: 9.6.18
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

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

docs/requirements.txt

@@ -1,7 +1,7 @@
 mkdocs-awesome-pages-plugin==2.10.1
 mkdocs-d2-plugin==1.6.0
 mkdocs-git-revision-date-localized-plugin==1.4.7
-mkdocs-material==9.6.17
+mkdocs-material==9.6.18
 mkdocs-minify-plugin==0.8.0
 mkdocs-redirects==1.2.2
 mkdocs-render-swagger-plugin==0.1.2