build: bump mkdocs-material from 9.5.19 to 9.5.20 in /.github/workflows

Bumps [mkdocs-material](https://github.com/squidfunk/mkdocs-material) from 9.5.19 to 9.5.20.
- [Release notes](https://github.com/squidfunk/mkdocs-material/releases)
- [Changelog](https://github.com/squidfunk/mkdocs-material/blob/master/CHANGELOG)
- [Commits](squidfunk/mkdocs-material@9.5.19...9.5.20)

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

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

.github/workflows/mkdocs-requirements.in

@@ -1,2 +1,2 @@
 mike==2.0.0
-mkdocs-material==9.5.19
+mkdocs-material==9.5.20

.github/workflows/mkdocs-requirements.txt

@@ -14,7 +14,7 @@ mergedeep==1.3.4
 mike==2.0.0
 mkdocs==1.6.0
 mkdocs-get-deps==0.2.0
-mkdocs-material==9.5.19
+mkdocs-material==9.5.20
 mkdocs-material-extensions==1.3
 packaging==22.0
 paginate==0.5.6