Revert "fix: remove unnecessary role attributes from tab-related buttons"

This reverts commit 4c68273.

Author: aojunhao123

src/TabNavList/AddButton.tsx

@@ -18,6 +18,7 @@ const AddButton = React.forwardRef<HTMLButtonElement, AddButtonProps>((props, re
     <button
       ref={ref}
       type="button"
+      role='tab'
       className={`${prefixCls}-nav-add`}
       style={style}
       aria-label={locale?.addAriaLabel || 'Add tab'}

src/TabNavList/TabNode.tsx

@@ -126,6 +126,7 @@ const TabNode: React.FC<TabNodeProps> = props => {
       {removable && (
         <button
           type="button"
+          role="tab"
           aria-label={removeAriaLabel || 'remove'}
           tabIndex={active ? 0 : -1}
           className={`${tabPrefix}-remove`}