fix: update release workflow

.github/workflows/ci.yml

@@ -11,7 +11,7 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        node: [12, 14, 16]
+        node: [16]
     steps:
     - name: Checkout
       uses: actions/checkout@v2

.github/workflows/release.yml

@@ -15,7 +15,7 @@ jobs:
       - name: Setup Node.js
         uses: actions/setup-node@v2
         with:
-          node-version: 12
+          node-version: 16
       - name: Install dependencies
         run: npm ci
       - name: Validate package-lock.json changes