How to Hide the "Scheduled Content Update" Admin Menu

function plt_hide_content_update_scheduler_menus() {
	//Hide the "Settings → Scheduled Content Update" menu.
	remove_submenu_page('options-general.php', 'tsu');
}

add_action('admin_menu', 'plt_hide_content_update_scheduler_menus', 11);

Where do I put this code?