ci: configure git safe.directory at system level

Added `git config --system --add safe.directory /github/workspace/docs/build/html` to the CI/CD pipeline.

- Configured git to recognize the documentation build directory as safe at the system level.
- Prevented potential permission issues during the upload process to GitHub Pages.

This change ensures smooth and error-free deployment of the WML documentation to GitHub Pages by addressing directory safety concerns.

.github/workflows/host_docs.yaml

@@ -46,7 +46,7 @@ jobs:
           git add -A
           git config --local user.email "[email protected]"
           git config --local user.name "GitHub Action"
-          git config --global --add safe.directory /github/workspace/docs/build/html
+          git config --system --add safe.directory /github/workspace/docs/build/html
           git commit -m 'deploy'
 
       - name: Force push to destination branch