fix(Pagination): add selectComponentClass prop type

[werheng]

Pagination 组件的 selectComponentClass 属性实际上可以是一个具体的组件，类似于 MiniSelect 或者 MiddleSelect，可以用于替换条数选择器的 Select 组件使其更易扩展，但是目前 selectComponentClass 被限制为 String 类型，希望能再增加 Object 的类型。

const paginationProps = {
  ...restProps,
  ...getIconsProps(prefixCls.value),
  prefixCls: prefixCls.value,
  selectPrefixCls: selectPrefixCls.value,
  selectComponentClass: selectComponentClass || (isSmall ? MiniSelect : MiddleSelect),
  locale: locale.value,
  buildOptionText,
  ...attrs,
  class: classNames(
    {
      [`${prefixCls.value}-mini`]: isSmall,
      [`${prefixCls.value}-rtl`]: direction.value === 'rtl',
    },
    attrs.class,
    hashId.value,
  ),
  itemRender,
};

[github-actions]

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