Missing drush/drush dependency

Problem/Motivation

While the module does work without Drush, it only provides its functionality during cron runs.

Steps to reproduce

1. composer require drupal/node_access_rebuild_progressive without having Drush.
2. drush node-access-rebuild-progressive

Proposed resolution

Add drush/drush dependency to composer.json.

Remaining tasks

Discuss, decide, patch, commit, release.

User interface changes

None.

API changes

None.

Data model changes

None.