Enhance Git worktree handling in documentation update workflow

- Improve pages branch checkout and update logic
- Add explicit fetch and pull for the pages branch
- Ensure robust handling of existing and new pages branches

Author: Chivier

.github/workflows/update_docs.yml

@@ -61,8 +61,16 @@ jobs:
           # Create and switch to a new worktree for the pages branch
           git worktree add --detach pages
           cd pages
+          
+          # Fetch and checkout pages branch, create if it doesn't exist
+          git fetch origin pages || true
           git checkout pages || git checkout --orphan pages
           
+          # If the branch exists, pull latest changes
+          if git rev-parse --verify origin/pages >/dev/null 2>&1; then
+            git pull origin pages
+          fi
+          
           # Remove existing files to prepare for new content
           git rm -rf . || true