InferenceResponse error code is lost in Python BLS

[ShuaiShao93]

Description
When we receive InferenceResponse from another model in Python BLS, the error code in it is lost and always reset to INTERNAL no matter what is actually returned.

Triton Information
What version of Triton are you using?
24.09

Are you using the Triton container or did you build it yourself?
Triton container

To Reproduce

1. Develop a model A that returns

pb_utils.InferenceResponse(
    error=pb_utils.TritonError(
        "unsupported feature",
        pb_utils.TritonError.UNSUPPORTED,
    )
)

2. Develop a model B as a BLS that calls into model A, and inspect the response error code

if infer_response.has_error():
    assert False, infer_response.error().code()

3. Get <__ErrorCode.INTERNAL: 1>

Expected behavior
The error code should be UNSUPPORTED

[caoyuan0816]

+1 for that issue, we are seeing exactly same issue here, anyone take a look of it?