ci: use checkout action v4

.github/workflows/pkg.pr.new.yml

@@ -25,7 +25,7 @@ jobs:
         node-version: [20]
     steps:
       - name: Checkout code
-        uses: actions/checkout@v2
+        uses: actions/checkout@v4
 
       - run: corepack enable
       - uses: actions/setup-node@v4