chore: different refactors

src/Plugins/Parallel/Contracts/HandlersWorkerArguments.php

@@ -0,0 +1,14 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Pest\Plugins\Parallel\Contracts;
+
+interface HandlersWorkerArguments
+{
+    /**
+     * @param  array<int, string>  $arguments
+     * @return array<int, string>
+     */
+    public function handleWorkerArguments(array $arguments): array;
+}