Bump mkdocs-material from 9.1.7 to 9.1.8

Bumps [mkdocs-material](https://github.com/squidfunk/mkdocs-material) from 9.1.7 to 9.1.8.
- [Release notes](https://github.com/squidfunk/mkdocs-material/releases)
- [Changelog](https://github.com/squidfunk/mkdocs-material/blob/master/CHANGELOG)
- [Commits](squidfunk/mkdocs-material@9.1.7...9.1.8)

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

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]

pyproject.toml

@@ -51,7 +51,7 @@ docs-gen = [
     "mike == 1.1.2",
     "mkdocs-gen-files == 0.4.0",
     "mkdocs-literate-nav == 0.6.0",
-    "mkdocs-material == 9.1.7",
+    "mkdocs-material == 9.1.8",
     "mkdocs-section-index == 0.3.5",
     "mkdocstrings[python] == 0.21.2",
 ]