Revert changes to connect_distributed_test.py for the new async Consumer

test_id:    kafkatest.tests.connect.connect_distributed_test.ConnectDistributedTest.test_exactly_once_source.clean=False.connect_protocol=eager.metadata_quorum=ISOLATED_KRAFT.use_new_coordinator=True.group_protocol=consumer
status:     FAIL
run time:   6 minutes 3.899 seconds


    InsufficientResourcesError('Not enough nodes available to allocate. linux nodes requested: 1. linux nodes available: 0')
Traceback (most recent call last):
  File "/home/jenkins/workspace/system-test-kafka-branch-builder/kafka/venv/lib/python3.7/site-packages/ducktape/tests/runner_client.py", line 184, in _do_run
    data = self.run_test()
  File "/home/jenkins/workspace/system-test-kafka-branch-builder/kafka/venv/lib/python3.7/site-packages/ducktape/tests/runner_client.py", line 262, in run_test
    return self.test_context.function(self.test)
  File "/home/jenkins/workspace/system-test-kafka-branch-builder/kafka/venv/lib/python3.7/site-packages/ducktape/mark/_mark.py", line 433, in wrapper
    return functools.partial(f, *args, **kwargs)(*w_args, **w_kwargs)
  File "/home/jenkins/workspace/system-test-kafka-branch-builder/kafka/tests/kafkatest/tests/connect/connect_distributed_test.py", line 919, in test_exactly_once_source
    consumer_validator = ConsoleConsumer(self.test_context, 1, self.kafka, self.source.topic, consumer_timeout_ms=1000, print_key=True)
  File "/home/jenkins/workspace/system-test-kafka-branch-builder/kafka/tests/kafkatest/services/console_consumer.py", line 97, in __init__
    BackgroundThreadService.__init__(self, context, num_nodes)
  File "/home/jenkins/workspace/system-test-kafka-branch-builder/kafka/venv/lib/python3.7/site-packages/ducktape/services/background_thread.py", line 26, in __init__
    super(BackgroundThreadService, self).__init__(context, num_nodes, cluster_spec, *args, **kwargs)
  File "/home/jenkins/workspace/system-test-kafka-branch-builder/kafka/venv/lib/python3.7/site-packages/ducktape/services/service.py", line 107, in __init__
    self.allocate_nodes()
  File "/home/jenkins/workspace/system-test-kafka-branch-builder/kafka/venv/lib/python3.7/site-packages/ducktape/services/service.py", line 217, in allocate_nodes
    self.nodes = self.cluster.alloc(self.cluster_spec)
  File "/home/jenkins/workspace/system-test-kafka-branch-builder/kafka/venv/lib/python3.7/site-packages/ducktape/cluster/cluster.py", line 54, in alloc
    allocated = self.do_alloc(cluster_spec)
  File "/home/jenkins/workspace/system-test-kafka-branch-builder/kafka/venv/lib/python3.7/site-packages/ducktape/cluster/finite_subcluster.py", line 31, in do_alloc
    allocated = self._available_nodes.remove_spec(cluster_spec)
  File "/home/jenkins/workspace/system-test-kafka-branch-builder/kafka/venv/lib/python3.7/site-packages/ducktape/cluster/node_container.py", line 117, in remove_spec
    raise InsufficientResourcesError("Not enough nodes available to allocate. " + msg)
ducktape.cluster.node_container.InsufficientResourcesError: Not enough nodes available to allocate. linux nodes requested: 1. linux nodes available: 0