Optimize the code that checks for duplicate patterns

Problem/Motivation

UserRestrictionsFormBase::validationForm() contains the following code.

    // Check for duplicate pattern.
    $existing = $this->entityTypeManager
      ->getStorage('user_restriction')
      ->loadByProperties([
        'rule_type' => $form_state->getValue('rule_type'),
        'pattern' => $form_state->getValue('pattern'),
      ]);
    /** @var \Drupal\Core\Entity\EntityFormInterface $form_object */
    $form_object = $form_state->getFormObject();

    if ($original_id = $form_object->getEntity()->getOriginalId()) {
      unset($existing[$original_id]);
    }

The code can be optimized, and search for restrictions with an ID that is different from the ID used by the edited restriction, which use the same pattern and the same rule type.
There is no need to check the original ID, since the ID cannot be changed after the restriction has been saved.

Proposed resolution

Replace that code with the following one.

$query = $this->entityTypeManager->getStorage('user_restriction')
  ->getQuery()
  ->accessCheck(FALSE)
  ->condition('id', $form_state->getValue('id'), '<>')
  ->condition('rule_type', $form_state->getValue('rule_type'))
  ->condition('pattern', $form_state->getValue('pattern'));
$existing = $query->execute();