chore(ci): test on current/future-LTS Node 20 (#498)

Author: nihalgonsalves

.github/workflows/test.yml

@@ -7,14 +7,21 @@ jobs:
       - uses: actions/checkout@v3
       - uses: actions/setup-node@v3
         with:
-          node-version: 18
+          node-version: 20
       - name: Install deps, build, then clear deps
         run: |
           npm ci
           npm run build
           rm -rf node_modules
+      - name: Test on Node 20
+        run: |
+          node -v
+          npm run test
       # Not using a matrix here since it's simpler
       # to just duplicate it and not spawn new instances
+      - uses: actions/setup-node@v3
+        with:
+          node-version: 18
       - name: Test on Node 18
         run: |
           node -v