CTaskTags::Rename

static function Rename($OLD_NAME, $NEW_NAME, $USER_ID)
{
	// $tasks = [];
	$list = LabelTable::getList([
		"select" => ['ID', "USER_ID", "NAME", 'GROUP_ID'],
		"filter" => [
			"=USER_ID" => intval($USER_ID),
			"=NAME" => $OLD_NAME,
			'=GROUP_ID' => 0,
		],
	])->fetchAll();
	$id = array_map(static function($el): int{
		return (int)$el['ID'];
	}, $list);

	if (count($id) !== 1)
	{
		return false;
	}
	$id = $id[0];

	$result = LabelTable::update($id,[
		'NAME' => $NEW_NAME,
	]);

	return $result->isSuccess();
}