ci: don't trigger review on PR updates (#5574)

Author: Xuanwo

.github/workflows/claude-code-review.yml

@@ -2,7 +2,7 @@ name: Claude Code Review
 
 on:
   pull_request_target:
-    types: [opened, synchronize]
+    types: [opened]
     # Optional: Only run on specific file changes
     # paths:
     #   - "src/**/*.ts"