Update mkdocs-material requirement from ==9.5.* to ==9.6.*

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@9.5.0...9.6.22)

---
updated-dependencies:
- dependency-name: mkdocs-material
  dependency-version: 9.6.22
  dependency-type: direct:development
...

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

Author: dependabot[bot]

requirements/dev.txt

@@ -1,7 +1,7 @@
 wget
 bump2version ==1.0.1
 # coverage >=4.5.4
-mkdocs-material ==9.5.*
+mkdocs-material ==9.6.*
 ipython[notebook] >8.0, <9.0
 mkdocstrings[python] ==0.26.*; python_version < "3.9"
 mkdocstrings[python] ==0.29.*; python_version >= "3.9"