chore: fix phpstan errors

src/Form/Service/Condition/RoomSelectionCondition.php

@@ -17,9 +17,9 @@ use App\Form\Service\Contract\FieldConditionInterface;
  */
 class RoomSelectionCondition implements FieldConditionInterface
 {
-    private const MATCH_MODE_EXACT = 'exact';
     private const MATCH_MODE_PREFIX = 'prefix';
 
+    /** @var list<string> */
     private array $requiredRoomCodes;
     private string $matchMode;