Add Node 21 to CI

Author: drwpow

.github/workflows/ci.yml

@@ -35,11 +35,12 @@ jobs:
           version: latest
       - run: pnpm i
       - run: pnpm run lint
-  test-node-versions:
+  test:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        node-version: [18.x, 20.x]
+        node-version: [18.x, 20.x, 21.x]
+    runs-on: ${{ matrix.os }}
     steps:
       - uses: actions/checkout@v3
       - uses: actions/setup-node@v3