CI Failure (Failed to initialize Producer ID: Broker: Not coordinator) in TxUpgradeTest. upgrade_does_not_change_tx_coordinator_assignment_test

[michael-redpanda]

https://ci-artifacts.dev.vectorized.cloud/vtools/14946/01903b5e-a0d3-45b2-a46b-d0492e1bd5d9

Module: rptest.transactions.transactions_test
Class:  TxUpgradeTest
Method: upgrade_does_not_change_tx_coordinator_assignment_test

test_id:    rptest.transactions.transactions_test.TxUpgradeTest.upgrade_does_not_change_tx_coordinator_assignment_test
status:     FAIL
run time:   2 minutes 51.091 seconds


    KafkaException(KafkaError{code=NOT_COORDINATOR,val=16,str="Failed to initialize Producer ID: Broker: Not coordinator"})
Traceback (most recent call last):
  File "/opt/.ducktape-venv/lib/python3.10/site-packages/ducktape/tests/runner_client.py", line 184, in _do_run
    data = self.run_test()
  File "/opt/.ducktape-venv/lib/python3.10/site-packages/ducktape/tests/runner_client.py", line 276, in run_test
    return self.test_context.function(self.test)
  File "/root/tests/rptest/services/cluster.py", line 105, in wrapped
    r = f(self, *args, **kwargs)
  File "/root/tests/rptest/transactions/transactions_test.py", line 1506, in upgrade_does_not_change_tx_coordinator_assignment_test
    self._populate_tx_coordinator(topic.name)
  File "/root/tests/rptest/transactions/transactions_test.py", line 1462, in _populate_tx_coordinator
    producer.init_transactions()
cimpl.KafkaException: KafkaError{code=NOT_COORDINATOR,val=16,str="Failed to initialize Producer ID: Broker: Not coordinator"}

JIRA Link: CORE-4273

[travisdowns]

ci-ignore because PT doesn't like the link