CI Failure (key symptom) in `ClusterBootstrapUpgrade.test_change_bootstrap_configs_after_upgrade`

[vbotbuildovich]

https://buildkite.com/redpanda/vtools/builds/14984 https://buildkite.com/redpanda/vtools/builds/14984 https://buildkite.com/redpanda/vtools/builds/14999 https://buildkite.com/redpanda/vtools/builds/14999

Module: rptest.tests.cluster_bootstrap_test
Class: ClusterBootstrapUpgrade
Method: test_change_bootstrap_configs_after_upgrade
Arguments: {
    "empty_seed_starts_cluster": true
}

test_id:    ClusterBootstrapUpgrade.test_change_bootstrap_configs_after_upgrade
status:     FAIL
run time:   8.877 seconds

TypeError("cannot pickle '_thread.lock' object")
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 "/opt/.ducktape-venv/lib/python3.10/site-packages/ducktape/mark/_mark.py", line 535, in wrapper
    return functools.partial(f, *args, **kwargs)(*w_args, **w_kwargs)
  File "/home/ubuntu/redpanda/tests/rptest/services/cluster.py", line 105, in wrapped
    r = f(self, *args, **kwargs)
  File "/home/ubuntu/redpanda/tests/rptest/tests/cluster_bootstrap_test.py", line 130, in test_change_bootstrap_configs_after_upgrade
    self.redpanda.rolling_restart_nodes(self.redpanda.nodes)
  File "/home/ubuntu/redpanda/tests/rptest/services/redpanda.py", line 1457, in rolling_restart_nodes
    restarter.restart_nodes(nodes,
  File "/home/ubuntu/redpanda/tests/rptest/services/rolling_restarter.py", line 100, in restart_nodes
    self.redpanda.start_node(
  File "/home/ubuntu/redpanda/tests/rptest/services/redpanda.py", line 3015, in start_node
    self.write_node_conf_file(
  File "/home/ubuntu/redpanda/tests/rptest/services/redpanda.py", line 3982, in write_node_conf_file
    conf = yaml.dump(doc)
  File "/opt/.ducktape-venv/lib/python3.10/site-packages/yaml/__init__.py", line 253, in dump
    return dump_all([data], stream, Dumper=Dumper, **kwds)
  File "/opt/.ducktape-venv/lib/python3.10/site-packages/yaml/__init__.py", line 241, in dump_all
    dumper.represent(data)
  File "/opt/.ducktape-venv/lib/python3.10/site-packages/yaml/representer.py", line 27, in represent
    node = self.represent_data(data)
  File "/opt/.ducktape-venv/lib/python3.10/site-packages/yaml/representer.py", line 48, in represent_data
    node = self.yaml_representers[data_types[0]](self, data)
  File "/opt/.ducktape-venv/lib/python3.10/site-packages/yaml/representer.py", line 207, in represent_dict
    return self.represent_mapping('tag:yaml.org,2002:map', data)
  File "/opt/.ducktape-venv/lib/python3.10/site-packages/yaml/representer.py", line 118, in represent_mapping
    node_value = self.represent_data(item_value)
  File "/opt/.ducktape-venv/lib/python3.10/site-packages/yaml/representer.py", line 48, in represent_data
    node = self.yaml_representers[data_types[0]](self, data)
TypeError: cannot pickle '_thread.lock' object

JIRA Link: CORE-5049