test(java): enable ref copy for non-serializable JDK class copy test

Author: sjahedhussini

java/fory-core/src/test/java/org/apache/fory/ForyCopyTest.java

@@ -462,6 +462,7 @@ public void testCopyNonSerializableJdkClass(){
 
     Fory fory = Fory.builder()
             .withLanguage(Language.JAVA)
+            .withRefCopy(true)
             .requireClassRegistration(false)
             .build();
     Package pkg = String.class.getPackage();