设置 `bordered: false` 当数据为空时，空内容下仍有一条线

看了下 样式是把空内容也放到了一个 td 里，是否应该 emptyplaceholder 放在 table 外部？

    if (data.length) {
   // ...
    } else {
      rows = (
        <ExpandedRow
          expanded
          className={`${prefixCls}-placeholder`}
          prefixCls={prefixCls}
          fixHeader={fixHeader}
          fixColumn={horizonScroll}
          horizonScroll={horizonScroll}
          component={trComponent}
          componentWidth={componentWidth}
          cellComponent={tdComponent}
          colSpan={flattenColumns.length}
        >
          {emptyNode}
        </ExpandedRow>
      );

Locate the empty-data branch shown in the issue, where ExpandedRow renders emptyNode with the table placeholder class. Reproduce the case with bordered set to false and no data, then verify that the empty table content no longer leaves a line; the payload names no file or test to start from.