chore: restore vendor directory dependencies

vendor/sebastian/code-unit/src/InterfaceMethodUnit.php

@@ -0,0 +1,21 @@
+<?php declare(strict_types=1);
+/*
+ * This file is part of sebastian/code-unit.
+ *
+ * (c) Sebastian Bergmann <sebastian@phpunit.de>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+namespace SebastianBergmann\CodeUnit;
+
+/**
+ * @immutable
+ */
+final readonly class InterfaceMethodUnit extends CodeUnit
+{
+    public function isInterfaceMethod(): bool
+    {
+        return true;
+    }
+}