fix: Remove duplicate "registryClient.close" method calls (#5805)

Co-authored-by: wen-hemin <wenhemin@apache.com>

dolphinscheduler-server/src/main/java/org/apache/dolphinscheduler/server/master/registry/ServerNodeManager.java

@@ -378,7 +378,6 @@ public class ServerNodeManager implements InitializingBean {
     @PreDestroy
     public void destroy() {
         executorService.shutdownNow();
-        registryClient.close();
     }
 
 }