Previously, in ExecutorServiceParallelExecutor, if an exception
occurred during registry cleanup (such as a timeout inside
DoFn teardown), the pipeline state was transitioned to terminal
before the exception was queued in `visibleUpdates`.

This introduced a race condition where `waitUntilFinish()` could
detect the terminal state and exit successfully before the
exception was offered to the updates queue, swallowing the exception.

This caused tests like `CallTest.givenTeardownTimeout_throwsError`
to fail since they expected the pipeline to throw an exception.
This change swaps the order so that the exception is posted to
`visibleUpdates` before updating the pipeline state to terminal,
ensuring the exception is always propagated.