Remove internal registry. (#3465)

Project/Packages/manifest.json

     "com.unity.modules.wind": "1.0.0",
     "com.unity.modules.xr": "1.0.0"
   },
-  "registry": "https://artifactory.prd.cds.internal.unity3d.com/artifactory/api/npm/upm-candidates",
   "testables" : [
     "com.unity.ml-agents"
   ]