[Bug Report] Title picker组件外置一个按钮来进行保存，但是值有时候不及时刷新

[7hao123]

Reproduction Link

no

Vant Version

4.8.5

Describe the Bug

经过我的多次测试，如果在滑动的过程中点确定按钮的话，会导致保存的还是上次的值。

Reproduce Steps

`

<van-picker
:columns="columns"
ref="picker"
defaultValue=""
confirm-button-text=""
cancel-button-text=""
toolbar-position="top"
title="时间"
v-model="defaultValue"

/> <van-button class="btn-down" round type="primary" color="#FF8519" @click="toDown"> queding

`

Device / Browser

No response