PHP deprecated implicit nullable types

Problem

There has been no commerce 2.x release with fixes for deprecation warnings like "Implicitly marking parameter $store as nullable is deprecated, the explicit nullable type must be used instead.

Solution

The provided patch applies to drupal/commerce:8.x-2.40 and changes all implicit nullable types to explicit nullable types.

Request

Projects still depending on 2.x exist. A patch release for 2.x users would be appreciated.