feat(pipeline-tasks): 任务更新推送。

src/pipeline-tasks/pipeline-tasks.resolver.ts

@@ -29,6 +29,15 @@ export class PipelineTasksResolver {
     return asyncIterator;
   }
 
+  @Subscription(() => PipelineTask, {
+    resolve: (value) => {
+      return value;
+    },
+  })
+  async pipelineTaskChanged(@Args('id') id: string) {
+    return await this.service.watchTaskUpdated(id);
+  }
+
   @Query(() => [PipelineTask])
   async listPipelineTaskByPipelineId(@Args('pipelineId') pipelineId: string) {
     return await this.service.listTasksByPipelineId(pipelineId);