[bug report] when dragging the scroll bar theader and tbody when there are many columns in the table component, there will be a short dislocation when dragging, and the dislocation will stop at the end of dragging, so it will cause the feeling of shaking during dragging

### Element UI version
2.15.0

### OS/Browsers version
Chrome 版本 96.0.4664.45

### Vue version
2.6.12

### Reproduction Link
https://codepen.io/dsdoreen/pen/eYGJWeR

### Steps to reproduce
1.打开表格页面 2.拖动拥有很多列的表格横向滚动条 3.来回拖拽滚动条 4.缓慢拖动至横向滚动条最右侧 来回拖动 注视表头和tbody 5.缓慢拖动时表头发现晃动

### What is Expected?
拖动拥有很多列的表格横向滚动条来回拖动时 无晃动的感觉 （thead和tbody拖动时保持同步）

### What is actually happening?
拖动拥有很多列的表格横向滚动条来回拖动时 有晃动的感觉 （thead和tbody拖动时未保持同步）