Removed 3 unnecessary stubbing in CleanLostNodesWorkTest.java

[ARUS2023]

Testing done

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In our analysis of the project, we observed that
3 unnecessary stubbing which stubbed getClient method, getProjectId method, getInstanceId in setUp are created but are never executed by 2 tests CleanLostNodesWorkTest.shouldRegisterCleanNodeWorker, CleanLostNodesWorkTest.shouldRegisterCleanNodeWorker.

Unnecessary stubbings are stubbed method calls that were never realized during test execution. Mockito recommends to remove unnecessary stubbings (https://www.javadoc.io/doc/org.mockito/mockito-core/latest/org/mockito/exceptions/misusing/UnnecessaryStubbingException.html).

We propose below a solution to remove the unnecessary stubbings.