add covers list and attributes mutator

src/Factories/Covers/CoversFunction.php

@@ -0,0 +1,16 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Pest\Factories\Covers;
+
+/**
+ * @internal
+ */
+final class CoversFunction
+{
+    public function __construct(public string $function)
+    {
+        //
+    }
+}