Wrong/Missing variable type hint for $row property of MigrateProcessTestCase class

Problem/Motivation

The MigrateProcessTestCase base class defines the protected $row property as \Drupal\migrate\Row variable type. Later in the code, the variable is mocked as migrate row and thus has also to be typed as \PHPUnit\Framework\MockObject\MockObject.

Steps to reproduce

• Check code of Drupal\Tests\migrate\Unit\process\MigrateProcessTestCase or run a static code analysis for that class

Proposed resolution

• Define variable type hinting as \Drupal\migrate\MigrateExecutable|\PHPUnit\Framework\MockObject\MockObject

Remaining tasks

• Done: Fix variable type

User interface changes

n/a

API changes

n/a

Data model changes

n/a

Release notes snippet

Use correct variable type hint for $row property of Drupal\Tests\migrate\Unit\process\MigrateProcessTestCase