Issue #3500683 by berdir, nod_, kristiaanvandeneynde, catch: Backport...

<?php

namespace Drupal\Core\Cache;

/**

 * Indicates that caching is optional.

 *

 * This interface is backported to Drupal 10.5 to make it easier to support it,

 * There are no usages in Drupal core before 11.2

 */

interface CacheOptionalInterface {

}