D12: fix RangeAsteriksValidator::validate() signature for Symfony 8

Symfony 8's ConstraintValidator::validate() is now typed (mixed $value, Constraint $constraint): void. RangeAsteriksValidator::validate($items, Constraint $constraint) (no types) is a fatal "Declaration must be compatible" error under Symfony 8 / Drupal core 12. Fix: widen params to match the parent exactly. No behavior change.