CI Failure (key symptom) in `SIAdminApiTest.test_bucket_validation`

[vbotbuildovich]

https://buildkite.com/redpanda/vtools/builds/15023

Module: rptest.tests.shadow_indexing_admin_api_test
Class: SIAdminApiTest
Method: test_bucket_validation
Arguments: {
    "cloud_storage_type": 1
}

test_id:    SIAdminApiTest.test_bucket_validation
status:     FAIL
run time:   138.341 seconds

TimeoutError("truncation couldn't be verified for topic='topic-dfaqtjjuqt' and target_bytes=2097152. last run partition_sizes=[9287294, 9287294, 9287294]")
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/shadow_indexing_admin_api_test.py", line 103, in test_bucket_validation
    wait_for_local_storage_truncate(self.redpanda,
  File "/home/ubuntu/redpanda/tests/rptest/util.py", line 287, in wait_for_local_storage_truncate
    wait_until(
  File "/opt/.ducktape-venv/lib/python3.10/site-packages/ducktape/utils/util.py", line 57, in wait_until
    raise TimeoutError(err_msg() if callable(err_msg) else err_msg) from last_exception
ducktape.errors.TimeoutError: truncation couldn't be verified for topic='topic-dfaqtjjuqt' and target_bytes=2097152. last run partition_sizes=[9287294, 9287294, 9287294]

JIRA Link: CORE-4557

[Mike Boquard]

Fixed by: #20310