[Chore] Change dismiss_stale_reviews to 1 (#17992)

Author: ruanwenjun

.asf.yaml

@@ -52,7 +52,7 @@ github:
           - "Title Validator"
       required_pull_request_reviews:
         dismiss_stale_reviews: true
-        required_approving_review_count: 2
+        required_approving_review_count: 1
   features:
     # Enable issues management
     issues: true