Change Patch::originalEntity variable type along to Drupal 11.2

Problem/Motivation

Since version 11.2 Drupal EntityBase class has variable $originalEntity defined as ?EntityInterface. We define this variable as not nullable EntityInterface that causes fatal error.

Steps to reproduce

To reproduce the error upgrade the core to version 11.2 - site will lay down in fatal error.

Proposed resolution

As we can't just remove this variable in favor of parent one to keep back compatibility with previous core versions, we can add nullable type «?EntityInterface» .

Remaining tasks

None

User interface changes

None

API changes

None

Data model changes

None