add pnpm step to workflows

Author: xgi

.github/workflows/build.yml

@@ -9,6 +9,10 @@ jobs:
     runs-on: ${{ matrix.os }}
     steps:
       - uses: actions/checkout@v4
+      - name: Install pnpm
+        uses: pnpm/action-setup@v4
+        with:
+          version: 9
       - uses: actions/setup-node@v4
         with:
           node-version: ${{ matrix.node }}

.github/workflows/publish.yml

@@ -12,6 +12,10 @@ jobs:
     runs-on: ${{ matrix.os }}
     steps:
       - uses: actions/checkout@v4
+      - name: Install pnpm
+        uses: pnpm/action-setup@v4
+        with:
+          version: 9
       - uses: actions/setup-node@v4
         with:
           node-version: ${{ matrix.node }}