GH-4057: Fix compilation warnings

Fixes #4057

Signed-off-by: Soby Chacko <[email protected]>

Author: sobychacko

spring-kafka/src/main/java/org/springframework/kafka/listener/adapter/MessagingMessageListenerAdapter.java

@@ -513,6 +513,7 @@ private RuntimeException checkAckArg(@Nullable Acknowledgment acknowledgment, Me
 	 * @param source the source data for the method invocation - e.g.
 	 * {@code o.s.messaging.Message<?>}; may be null
 	 */
+	@SuppressWarnings("try")
 	protected void handleResult(Object resultArg, Object request, @Nullable Acknowledgment acknowledgment,
 			@Nullable Consumer<?, ?> consumer, @Nullable Message<?> source) {
 		final Observation observation = getCurrentObservation();
@@ -550,7 +551,7 @@ else if (!(result instanceof CompletableFuture<?>)) {
 		}
 
 		completableFutureResult.whenComplete((r, t) -> {
-			try (var scope = observation.openScope()) {
+			try (var ignored = observation.openScope()) {
 				if (t == null) {
 					asyncSuccess(r, replyTopic, source, messageReturnType);
 					if (isAsyncReplies()) {