Fix TrigUpgradeTest unit test emu_step_processing
As explained in !29940 (comment 3152974) the fix was to simply revert 7347e43a. While looking at this test, I also fixed some python imports flagged by flake8.
Closes ATR-20849
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As explained in !29940 (comment 3152974) the fix was to simply revert 7347e43a. While looking at this test, I also fixed some python imports flagged by flake8.
Closes ATR-20849