refactor(task): 优化任务获取逻辑

- 在 TaskTaskServiceImpl 中添加 limit(1) 以限制获取的任务数量为 1
- 在 TaskMapper.xml 中移除 selectNotRunning 查询中的 limit 1条件

src/main/java/com/ycwl/basic/service/task/impl/TaskTaskServiceImpl.java

@@ -201,7 +201,7 @@ public class TaskTaskServiceImpl implements TaskService {
                         taskList = _taskList.stream().filter(task -> {
                             boolean workerSelfHostedScenic = isWorkerSelfHostedScenic(task.getScenicId());
                             return !workerSelfHostedScenic;
-                        }).toList();
+                        }).limit(1).toList();
                     }
                     resp.setTasks(taskList);
                     resp.setTemplates(updTemplateList);

src/main/resources/mapper/TaskMapper.xml

@@ -84,7 +84,6 @@
         from task
         where status = 0
           and worker_id is null
-        limit 1
     </select>
     <select id="selectAllNotRunning" resultType="com.ycwl.basic.model.pc.task.entity.TaskEntity">
         select *