fix: fix test with pnpm version

Author: headwindz

.github/workflows/test.yaml

@@ -13,9 +13,11 @@ jobs:
           - 16
     steps:
       - uses: actions/checkout@v2
-      - uses: actions/setup-node@v2
-        with:
-          node-version: ${{ matrix.node-version }}
-      - uses: pnpm/action-setup@v2
-      - run: pnpm i
-      - run: pnpm run test
+        - uses: actions/setup-node@v2
+          with:
+            node-version: ${{ matrix.node-version }}
+        - uses: pnpm/action-setup@v2
+          with:
+            version: 6
+        - run: pnpm i
+        - run: pnpm run test