Also run spec on modern Node versions in CI

Author: rubensworks

.github/workflows/ci.yml

@@ -67,10 +67,9 @@ jobs:
       matrix:
         os: [ubuntu-latest]
         node-version:
-          - 12.x
-          - 14.x
           - 16.x
           - 18.x
+          - 20.x
     steps:
       - name: Use Node.js ${{ matrix.node-version }}
         uses: actions/setup-node@v3