Put the arrow reference fixture PHP version constraint on its first line

Author: ondrejmirtes

tests/PHPStan/Rules/DeadCode/data/unused-variable-arrow-reference.php

@@ -1,5 +1,5 @@
-<?php
-// lint >= 8.0
+<?php // lint >= 8.0
+
 
 namespace UnusedVariableArrowReference;