ci: test on node 18 and 20

Author: B4nan

.github/workflows/tests.yml

@@ -7,7 +7,7 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        node-version: [14, 16]
+        node-version: [14, 16, 18, 20]
 
     steps:
     - uses: actions/checkout@v3