ci: change event trigger for deploy-ghpages workflow

.github/workflows/deploy-ghpages.yml

@@ -1,12 +1,12 @@
 name: Deploy to GitHub Pages
 
 on:
-  push:
-    branches:
-      - beta
-    # Review gh actions docs if you want to further define triggers, paths, etc
-    # https://docs.github.com/en/actions/using-workflows/workflow-syntax-for-github-actions#on
-
+  # https://docs.github.com/zh/actions/using-workflows/events-that-trigger-workflows#workflow_run
+  workflow_run:
+    workflows:
+      - 'Build and Release'
+    types:
+      - completed
 jobs:
   deploy:
     name: Deploy to GitHub Pages