[meta] Method getMockForAbstractClass() of class PHPUnit\Framework\TestCase is deprecated in PHPUnit 10

Problem/Motivation

Method getMockForAbstractClass() of class PHPUnit\Framework\TestCase is deprecated in PHPUnit 10.

Some uses were removed as part of #3217904: [meta] Support PHPUnit 10 in Drupal 11, but there's a relevant number of places where this is still used.

Proposed resolution

Track here replacement in the child issues.

Remaining tasks

User interface changes

API changes

Data model changes

Release notes snippet