Add pnpm install action

Author: Demivan

.github/workflows/ shipjs-trigger.yml

@@ -17,7 +17,9 @@ jobs:
         with:
           registry-url: "https://registry.npmjs.org"
           node-version: '14'
-      - run: pnpm i
+      - uses: pnpm/action-setup@v2.0.1
+        with:
+          run_install: true
       - run: npx shipjs trigger
         env:
           GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}

.github/workflows/test.yml

@@ -26,8 +26,9 @@ jobs:
         uses: actions/setup-node@v2.4.1
         with:
           node-version: ${{ matrix.node }}
-      - name: Install
-        run: pnpm i
+      - uses: pnpm/action-setup@v2.0.1
+        with:
+          run_install: true
 
       - name: Test
         run: pnpm test --coverage