When an If/Else branch skips an Iterator step (because the branch wasn't
taken), the executor incorrectly entered the iterator's loop body. This
happened because getNextStepIdsToExecute checked !hasProcessedAllItems
on an undefined result, which evaluated to true, causing it to return
initialLoopStepIds instead of the post-loop nextStepIds.
Fix: Add a !executedStepOutput.shouldSkipStepExecution guard to the
iterator condition in getNextStepIdsToExecute, consistent with the
existing shouldFailSafely guard.
