* fix(sagemaker): keep AWS credentials out of the sagemaker_chat request body
sagemaker_chat and sagemaker_nova built the container body from every optional
param, so aws_access_key_id, aws_secret_access_key, aws_session_token and the
other aws_* auth params, plus model_id and sagemaker_base_url, were sent in the
JSON body to the endpoint container. The request is still SigV4-signed with the
same credentials, which stay in optional_params for signing
* fix(sagemaker): limit the sagemaker_chat body filter to aws_ params
model_id and sagemaker_base_url are not credentials, so they stay in the
body as before and the change sticks to what the fix is about
* test(sagemaker): assert the whole sagemaker_chat request body
* fix(sagemaker): filter the sagemaker_chat body with the shared AWS auth param list
* test(sagemaker): cover the sagemaker_chat body on every endpoint, credential source, and outage
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Co-authored-by: mateo-berri <277851410+mateo-berri@users.noreply.github.com>
