dependencies: Upgrade mockito 3.5 to 4.5 (#2316)

* refactor: move tests of leader-followers into correct package

* dep: remove version constraint for Mockito in acyclic-visitor

* dep: remove version constraint for Mockito in caching

* chore: cleanup mockito-core import on some POMs

* dep: upgrade core.mocktio 3.5.6 to 4.5.1

"- org.mockito.Mockito#verifyZeroInteractions an alias of verifyNoMoreInteractions"
https://github.com/mockito/mockito/commit/caf35b24e2764df0498469526ecb3e7ec68a0430