[ci]更新GitHub Actions工作流中的Node.js环境设置，将Node.js版本设置为20.x，并调整相关步骤名称以提高可读性。

packages/stdf/.github/workflows/releases-demo.yml

@@ -12,11 +12,10 @@ jobs:
       - name: Checkout
         uses: actions/checkout@v4
 
-      - name: Install Node.js
-        uses: actions/setup-node@v4
+      - name: Setup Node.js environment
+        uses: actions/setup-node@v3
         with:
-          node-version: 20
-          cache: npm
+          node-version: 20.x
 
       - name: Install dependencies
         run: npm install