docs: Update migration for Select events (#23376)

* docs: Update migration for Select events

* Update migration-v4.en-US.md

docs/react/migration-v4.en-US.md

@@ -119,7 +119,7 @@ const Demo = () => (
   - [Date cell className of Custom style demo](/components/date-picker/#components-date-picker-demo-date-render) changed from `ant-calendar-date` to `ant-picker-cell-inner`.
 - Tree, Select, TreeSelect, AutoComplete rewrite
   - use virtual scrolling.
-  - `onBlur` no longer trigger value change.
+  - `onBlur` no longer trigger value change and return React origin `event` object instead.
   - AutoComplete no longer support `optionLabelProp`. Please set Option `value` directly.
   - Select remove `dropdownMenuStyle` prop.
   - Use `listHeight` to config popup height instead of `dropdownStyle`.

docs/react/migration-v4.zh-CN.md

@@ -119,7 +119,7 @@ const Demo = () => (
   - [自定义单元格样式](/components/date-picker-cn/#components-date-picker-demo-date-render)的类名从 `ant-calendar-date` 改为 `ant-picker-cell-inner`。
 - Tree、Select、TreeSelect、AutoComplete 重新写
   - 使用虚拟滚动。
-  - `onBlur` 时不再修改选中值。
+  - `onBlur` 时不再修改选中值，且返回 React 原生的 `event` 对象。
   - AutoComplete 不再支持 `optionLabelProp`，请直接设置 Option `value` 属性。
   - Select 移除 `dropdownMenuStyle` 属性。
   - 如果你需要设置弹窗高度请使用 `listHeight` 来代替 `dropdownStyle` 的高度样式。