Replace, in tests, mocks that do not configure doubles with their actual objects

Problem/Motivation

Noted in #3130606-34: MockBuilder::setMethods is deprecated in PHPUnit8 and removed from PHPUnit10, the usage of ::onlyMethods([]) smells like we do not need a mocks sometimes but rather use the acutal object.

Steps to reproduce

Proposed resolution

Remaining tasks

User interface changes

API changes

Data model changes

Release notes snippet