config: add pnpm to workflow

.github/workflows/build.yaml

@@ -16,11 +16,29 @@ permissions:
 jobs:
   amd64:
     runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        node-version: [ 15 ]
     permissions:
-      contents: read
       packages: write
+      contents: read
+      pull-requests: write
     steps:
       - uses: actions/checkout@v3
+      - name: Setup
+        uses: actions/setup-node@v3
+      - uses: pnpm/action-setup@v2
+        with:
+          version: 8
+      - name: Use Node.js ${{ matrix.node-version }}
+        uses: actions/setup-node@v3
+        with:
+          node-version: ${{ matrix.node-version }}
+          cache: 'pnpm'
+      - name: Install dependencies
+        run: pnpm install
+      - name: Build
+        run: pnpm build
       - name: Login to ghcr.io
         uses: docker/login-action@v2
         with: