build(deps-dev): update mkdocs-material requirement from ~8 to ~9 (#61)

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@8.0.0...9.4.6)

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

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

pyproject.toml

@@ -42,7 +42,7 @@ all = ["zeep", "ipython", "orjson"]
 black = "~23"
 flake8 = "~5"
 isort = "~5"
-mkdocs-material = "~8"
+mkdocs-material = "~9"
 mypy = "~1"
 pytest = "~7"
 pytest-cov = "~4"