Run tests against Node 20

Author: remcohaszing

.github/workflows/ci.yaml

@@ -43,7 +43,10 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        node-version: [16, 18]
+        node-version:
+          - 16
+          - 18
+          - 20
     steps:
       - uses: actions/checkout@v3
       - uses: actions/setup-node@v3