refactor(project-demand): 优化加载状态管理

- 在获取数据失败时添加 loading.value = false，确保正确更新加载状态

src/views/project-demand/summary/add.vue

@@ -836,6 +836,7 @@ const getDetailInfo = async () => {
       optionalChargeLeadershipList.value = formData.value.optionalChargeLeadership
       loading.value = false
     }else{
+      loading.value = false
       ElNotification({
         title: '提示',
         message: res.msg,