build(deps): update mkdocs-material[imaging] requirement

Updates the requirements on [mkdocs-material[imaging]](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@9.5.49...9.6.1)

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

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

Author: dependabot[bot]

requirements-free.txt

@@ -1,6 +1,6 @@
 # No Material Insiders
 # --------------------
 
-mkdocs-material[imaging]>=9.5.49,<9.6
+mkdocs-material[imaging]>=9.5.49,<9.7
 
 -r requirements.txt