Migrate ConfigController to Spring Boot 3

spring-projects/spring-framework#22154

Author: TeslaCN

shenyu-admin/src/main/java/org/apache/shenyu/admin/config/DataSyncConfiguration.java

@@ -91,12 +91,6 @@ static class HttpLongPollingListener {
         public HttpLongPollingDataChangedListener httpLongPollingDataChangedListener(final HttpSyncProperties httpSyncProperties) {
             return new HttpLongPollingDataChangedListener(httpSyncProperties);
         }
-
-        @Bean
-        @ConditionalOnMissingBean(ConfigController.class)
-        public ConfigController configController(final HttpLongPollingDataChangedListener httpLongPollingDataChangedListener) {
-            return new ConfigController(httpLongPollingDataChangedListener);
-        }
     }
 
     /**

shenyu-admin/src/main/java/org/apache/shenyu/admin/controller/ConfigController.java

@@ -23,6 +23,8 @@
 import org.apache.shenyu.admin.utils.ShenyuResultMessage;
 import org.apache.shenyu.common.dto.ConfigData;
 import org.apache.shenyu.common.enums.ConfigGroupEnum;
+import org.springframework.boot.autoconfigure.condition.ConditionalOnBean;
+import org.springframework.boot.autoconfigure.condition.ConditionalOnMissingBean;
 import org.springframework.web.bind.annotation.ResponseBody;
 import org.springframework.web.bind.annotation.RequestMapping;
 import org.springframework.web.bind.annotation.GetMapping;
@@ -31,13 +33,16 @@
 import jakarta.servlet.http.HttpServletRequest;
 import jakarta.servlet.http.HttpServletResponse;
 import jakarta.validation.constraints.NotNull;
+import org.springframework.web.bind.annotation.RestController;
+
 import java.util.Map;
 
 /**
  * This Controller only when HttpLongPollingDataChangedListener exist, will take effect.
  */
-@ResponseBody
+@RestController
 @RequestMapping("/configs")
+@ConditionalOnBean(HttpLongPollingDataChangedListener.class)
 public class ConfigController {
 
     private final HttpLongPollingDataChangedListener longPollingListener;