Add NodeJS 20.x to the build matrix

Author: lornajane

.github/workflows/tests.yml

@@ -13,7 +13,7 @@ jobs:
 
     strategy:
       matrix:
-        node-version: [14.x, 16.x, 18.x]
+        node-version: [14.x, 16.x, 18.x, 20.x]
 
     steps:
       - uses: actions/checkout@v3