CI: add Node.js 20

Author: XhmikosR

.github/workflows/test.yml

@@ -13,7 +13,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        node: [14, 16, 18]
+        node: [14, 16, 18, 20]
 
     steps:
       - name: Clone repository