use Node.js 16 in CI

Author: nabeta

.github/workflows/rubyonrails.yml

@@ -27,6 +27,10 @@ jobs:
     steps:
       - name: Checkout code
         uses: actions/checkout@v3
+      - name: Setup node
+        uses: actions/setup-node@v3
+        with:
+          node-version: 16
       # Add or replace dependency steps here
       - name: Install Ruby and gems
         uses: ruby/setup-ruby@v1