Deprecate for removal Jackson 2 support

This commit deprecate for removal (likely in a future 7.x release) the
Jackson 2 support in favor of the Jackson 3 one.

Closes gh-33798

spring-websocket/src/main/java/org/springframework/web/socket/sockjs/client/SockJsClient.java

@@ -97,6 +97,7 @@ public class SockJsClient implements WebSocketClient, Lifecycle {
 	 * otherwise is defaulted to {@link RestTemplateXhrTransport}.
 	 * @param transports the (non-empty) list of transports to use
 	 */
+	@SuppressWarnings("removal")
 	public SockJsClient(List<Transport> transports) {
 		Assert.notEmpty(transports, "No transports provided");
 		this.transports = new ArrayList<>(transports);

spring-websocket/src/main/java/org/springframework/web/socket/sockjs/frame/Jackson2SockJsMessageCodec.java

@@ -39,7 +39,10 @@ import org.springframework.util.Assert;
  *
  * @author Rossen Stoyanchev
  * @since 4.0
+ * @deprecated since 7.0 in favor of {@link JacksonJsonSockJsMessageCodec}
  */
+@Deprecated(since = "7.0", forRemoval = true)
+@SuppressWarnings("removal")
 public class Jackson2SockJsMessageCodec extends AbstractSockJsMessageCodec {
 
 	private final ObjectMapper objectMapper;

spring-websocket/src/main/java/org/springframework/web/socket/sockjs/transport/TransportHandlingSockJsService.java

@@ -109,6 +109,7 @@ public class TransportHandlingSockJsService extends AbstractSockJsService implem
 	 * initialized at start-up and shuts down when the application stops
 	 * @param handlers one or more {@link TransportHandler} implementations to use
 	 */
+	@SuppressWarnings("removal")
 	public TransportHandlingSockJsService(TaskScheduler scheduler, Collection<TransportHandler> handlers) {
 		super(scheduler);