chore: add Windows and macOS for test target

Author: uetchy

.github/workflows/test.yml

@@ -5,11 +5,12 @@ on:
 
 jobs:
   test:
-    name: Test (Node ${{ matrix.node }})
+    name: Test (${{ matrix.os }} / Node ${{ matrix.node }})
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        node: [12, 14, 16]
+        os: [ubuntu-latest, macos-latest, windows-latest]
+        node: [14, 16, 18]
     steps:
       - name: Checkout
         uses: actions/checkout@v2
@@ -19,10 +20,6 @@ jobs:
         with:
           node-version: ${{ matrix.node }}
 
-      - uses: pnpm/action-setup@v2.1.0
-        with:
-          version: 6.0.2
-
       - name: Install dependencies
         run: yarn install