Enforce REQUIRES_NEW for correct transaction configuration

Closes gh-31414

spring-tx/src/test/java/org/springframework/transaction/event/TransactionalApplicationListenerMethodAdapterTests.java

@@ -233,7 +233,7 @@ public class TransactionalApplicationListenerMethodAdapterTests {
 		}
 
 		@TransactionalEventListener
-		@Async @Transactional
+		@Async @Transactional(propagation = Propagation.REQUIRES_NEW)
 		public void withAsyncTransactionalAnnotation(String data) {
 		}
 	}