list all java versions we want to test

Author: TheSnoozer

.github/workflows/default-tests.yml

@@ -27,7 +27,15 @@ jobs:
       matrix:
         java_version: [
           '11',
-          # '12', '13', '14', '15', '16', '17', '18', '19', '20'
+          '12',
+          '13',
+          '14',
+          '15',
+          '16',
+          '17',
+          '18',
+          '19',
+          '20'
         ]
     steps:
       - uses: actions/checkout@v3