incremental fix

Author: chkuang-g

.github/workflows/test.yaml

@@ -3,7 +3,7 @@ name: Test
 on:
   workflow_dispatch:
     inputs:
-      unity_version:
+      unity_versions:
         description: 'Unity version (value: 2018, 2019, 2020. separated by commas)'
         default: '2019'
         required: true