ci: fix workflow

Author: 2color

.github/workflows/build.yml

@@ -19,6 +19,8 @@ jobs:
     steps:
       - name: Checkout code
         uses: actions/checkout@v4
+        with:
+          ref: ${{ github.event_name == 'pull_request_target' && github.event.pull_request.head.sha || github.sha }}
 
       - name: Setup Node.js
         uses: actions/setup-node@v4