Fix epoch logging on train epoch end

[rohitgr7]

What does this PR do?

Fixes #12851

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cc @otaj @Borda @carmocca @edward-io @ananthsub @rohitgr7 @kamil-kaczmarek @Raalsky @Blaizzy

[carmocca]

Removed the for loop inside the test, I think it's much easier to see this way and it's fine to unroll since it's not long