Rule source on GitHub

SetCookieOptionsArrayToArgumentsRector

Convert setcookie option array to arguments

-setcookie('name', $value, ['expires' => 360]);
+setcookie('name', $value, 360);

Configure your rector.php:

<?php

use Rector\Config\RectorConfig;
use Rector\DowngradePhp73\Rector\FuncCall\SetCookieOptionsArrayToArgumentsRector;

return RectorConfig::configure()
    ->withRules([
        SetCookieOptionsArrayToArgumentsRector::class,
    ]);