Update mkdocs-material requirement (#21)

Updates the requirements on [mkdocs-material](https://github.com/squidfunk/mkdocs-material) to permit the latest version.
- [Release notes](https://github.com/squidfunk/mkdocs-material/releases)
- [Changelog](https://github.com/squidfunk/mkdocs-material/blob/master/CHANGELOG)
- [Commits](squidfunk/mkdocs-material@8.1.4...9.5.1)

---
updated-dependencies:
- dependency-name: mkdocs-material
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <[email protected]>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

pyproject.toml

@@ -54,7 +54,7 @@ dev=[
 
 doc = [
     "mkdocs >=1.1.2,<2.0.0",
-    "mkdocs-material >=8.1.4,<9.0.0",
+    "mkdocs-material >=8.1.4,<10.0.0",
     "mkdocstrings-python",
     "mdx-include >=1.4.1,<2.0.0",
     "pillow >=9.3.0,<10.0.0",