Update ValidationExceptions.json

Adding the 2nd exception needed

Author: NoelStephensUnity

ValidationExceptions.json

@@ -4,7 +4,12 @@
       "ValidationTest": "API Validation",
       "ExceptionMessage": "Assembly \"Unity.Netcode.Editor.PackageChecker\" no longer exists or is no longer included in build. This change requires a new major version.",
       "PackageVersion": "2.4.1"
-    }
+    },
+    {    
+    "ValidationTest": "API Validation",    
+    "ExceptionMessage": "New assembly \"Unity.Netcode.PackageChecker.Editor\" may only be added in a new minor or major version.",    
+    "PackageVersion": "2.4.1"    
+    }    
   ],
   "WarningExceptions": []
-}
+}