Avoid using undefined variables with static array in trait

[tebeso]

• PHPMD version: 2.13.0
• PHP Version: 8.1
• Installation type: composer
• Operating System / Distribution & Version: Ubuntu 22.04

Current Behavior

<?php
use SomeTrait;

class Example {
   use SomeTrait;

   public function test(){
     $bla = self::$someTraitVar['someKey'];
   }
}
?>

<?php

trait SomeTrait {
   protected static array $someTraitVar = [
      'someKey' => 12345
   ];
}
?>

This will mark self::$someTraitVar['someKey']; within the test method as "Avoid using undefined variables...".

Expected Behavior

Should not be marked as "Avoid using undefined variables...".

Steps To Reproduce:

See example code above