SQS transport failing with no `MessageAttributeNames`

[cuducos]

After 5.6 I started to have this error:

  File "/rcp/.venv/lib/python3.13/site-packages/kombu/transport/SQS.py", line 594, in _get_bulk
    resp = self._receive_message(
        queue=queue,
        wait_time_seconds=self.wait_time_seconds,
        max_number_of_messages=max_count
    )
  File "/rcp/.venv/lib/python3.13/site-packages/kombu/transport/SQS.py", line 560, in _receive_message
    return client.receive_message(**params)
           ~~~~~~~~~~~~~~~~~~~~~~^^^^^^^^^^
  File "/rcp/.venv/lib/python3.13/site-packages/botocore/client.py", line 602, in _api_call
    return self._make_api_call(operation_name, kwargs)
           ~~~~~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^
  File "/rcp/.venv/lib/python3.13/site-packages/botocore/context.py", line 123, in wrapper
    return func(*args, **kwargs)
  File "/rcp/.venv/lib/python3.13/site-packages/botocore/client.py", line 1035, in _make_api_call
    request_dict = self._convert_to_request_dict(
        api_params=api_params,
    ...<3 lines>...
        headers=additional_headers,
    )
  File "/rcp/.venv/lib/python3.13/site-packages/botocore/client.py", line 1102, in _convert_to_request_dict
    request_dict = self._serializer.serialize_to_request(
        api_params, operation_model
    )
  File "/rcp/.venv/lib/python3.13/site-packages/botocore/validate.py", line 381, in serialize_to_request
    raise ParamValidationError(report=report.generate_report())
botocore.exceptions.ParamValidationError: Parameter validation failed:
Invalid type for parameter MessageAttributeNames, value: None, type: <class 'NoneType'>, valid types: <class 'list'>, <class 'tuple'>

I guess it has to do with #2300 and this dictionary get that might return None:

kombu/kombu/transport/SQS.py

Lines 549 to 550 in 4e74395

	message_attribute_names = self.get_message_attributes.get(
	'MessageAttributeNames')

Running with boto3==1.40.49 (released on Oct 9, 2025 — not the latest one but still…).

[auvipy]

hey, thanks for the report! can you contribute a fix?

[cuducos]

Sure thing. Since that part is mocked in the tests, I couldn't find how to properly test it — but here it is #2405