SimpleAsyncTaskScheduler stops accepting new tasks when isShutdown

This changes the criteria for simplified task rejection logging from
to be that the executor is in the shutdown phase, not fully terminated.

See gh-33334
Closes gh-33336

spring-context/src/main/java/org/springframework/scheduling/concurrent/SimpleAsyncTaskScheduler.java

@@ -201,7 +201,7 @@ public class SimpleAsyncTaskScheduler extends SimpleAsyncTaskExecutor implements
 	}
 
 	private void shutdownAwareErrorHandler(Throwable ex) {
-		if (this.scheduledExecutor.isTerminated()) {
+		if (this.scheduledExecutor.isShutdown()) {
 			LogFactory.getLog(getClass()).debug("Ignoring scheduled task exception after shutdown", ex);
 		}
 		else {