Update ci.yml

Author: Tinker-Twins

.github/workflows/ci.yml

@@ -20,7 +20,7 @@ jobs:
         with:
           key: ${{ github.ref }}
           path: .cache
-      - run: pip install mkdocs-material
+      - run: pip install mkdocs-material==9.5.29
       - run: pip install pillow cairosvg
       - run: pip install mkdocs-git-revision-date-localized-plugin
       - run: pip install mkdocs-glightbox