🐛 [Bug]: When nesting using Split, the mouse direction on the left and right split line is wrong when the upper and lower division is nested.

[Aostas]

Version

官网帮助文档演示

Vue Version

官网帮助文档演示

Link to minimal reproduction

https://opentiny.design/tiny-vue/zh-CN/os-theme/components/split#nested-use

Step to reproduce

1. 访问https://opentiny.design/tiny-vue/zh-CN/os-theme/components/split#nested-use
2. 点击显示代码按钮
3. 将左右分割嵌套上下分割改为上下分割嵌套左右分割，比如改为：

   
   <template>
   <div class="split-nest">
   <tiny-split v-model="split3" mode="vertical">
     <template #top>
       <div class="demo-split-pane no-padding">
         <tiny-split v-model="split4">
           <template #left>
             <div class="demo-split-pane">上左面板</div>
           </template>
           <template #right>
             <div class="demo-split-pane">上右面板</div>
           </template>
         </tiny-split>
       </div>
     </template>
     <template #bottom>
       <div class="demo-split-pane">下面板</div>
     </template>
   </tiny-split>
   </div>
   </template>

### What is expected

鼠标放在左右分割线上时，箭头应该是左右方向

### What is actually happening

鼠标放在左右分割线上时，箭头是上下方向
![20230717145735_rec_](https://github.com/opentiny/tiny-vue/assets/31911231/167b5887-90b2-44da-86fd-d6b32a699bd6)

### Any additional comments (optional)

_No response_

[horadrim1015]

没人回复吗，我也遇到这个bug了。