Bump mkdocs-material from 9.5.29 to 9.5.31 in /doc

Bumps [mkdocs-material](https://github.com/squidfunk/mkdocs-material) from 9.5.29 to 9.5.31.
- [Release notes](https://github.com/squidfunk/mkdocs-material/releases)
- [Changelog](https://github.com/squidfunk/mkdocs-material/blob/master/CHANGELOG)
- [Commits](squidfunk/mkdocs-material@9.5.29...9.5.31)

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

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

doc/requirements.txt

@@ -1,3 +1,3 @@
 mdx-truly-sane-lists==1.3
 mkdocs==1.6.0
-mkdocs-material==9.5.29
+mkdocs-material==9.5.31