[LARAVEL 8] include_factory_builders does not work anymore (#1047) (#1049)

* [LARAVEL 8] include_factory_builders does not work anymore (#1047)

* Change skip expression
Append comment about deprecated to config file
Append comment about deprecated to README file

tests/Factories/AllTest.php

@@ -0,0 +1,18 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Barryvdh\LaravelIdeHelper\Tests\Factories;
+
+use Barryvdh\LaravelIdeHelper\Factories;
+use PHPUnit\Framework\TestCase;
+
+class AllTest extends TestCase
+{
+    public function testAll(): void
+    {
+        $factories = Factories::all();
+
+        self::assertEmpty($factories);
+    }
+}