style(CollapsibleCalendar): 移除作业选择弹窗中的多余空行

 <!--
  * @Date: 2025-01-25 15:34:17
  * @LastEditors: hookehuyr hookehuyr@gmail.com
- * @LastEditTime: 2025-12-11 15:01:51
+ * @LastEditTime: 2025-12-11 15:22:15
  * @FilePath: /mlaj/src/components/ui/CollapsibleCalendar.vue
  * @Description: 可折叠日历组件
 -->
@@ -80,7 +80,6 @@
         <!-- 作业选择弹窗 -->
         <van-popup
             v-model:show="showCoursePicker"
-
             round
             position="bottom"
             :style="{ minHeight: '30%', maxHeight: '80%', width: '100%' }"