chore: add node 20.x to CI tests (#352)

Author: jeswr

.github/workflows/ci.yml

@@ -12,6 +12,7 @@ jobs:
           - 14.x
           - 16.x
           - 18.x
+          - 20.x
     steps:
       - name: Use Node.js ${{ matrix.node-version }}
         uses: actions/setup-node@v2