Unit testing cluster is used in two Scenes tests

[cecille]

Summary Title:

The unit testing cluster is not intended for production devices. It should not be used in tests

Description:

Unit testing appears in
src/app/tests/suites/certification/Test_TC_S_2_2.yaml: cluster: "Unit Testing"
src/app/tests/suites/certification/Test_TC_S_2_2.yaml: cluster: "Unit Testing"
src/app/tests/suites/certification/Test_TC_S_2_3.yaml: cluster: "Unit Testing"
src/app/tests/suites/certification/Test_TC_S_2_3.yaml: cluster: "Unit Testing"

Steps to reproduce:

grep -E 'cluster: "Unit Testing"' src/app/tests/suites/certification/*.yaml

[lpbeliveau-silabs]

Was fixed in project-chip/connectedhomeip#35130