`bentoml.save_config` always crashes with `yaml.representer.RepresenterError`

Description

bentoml.save_config(config_file_handle) is a public API exported from bentoml/__init__.py that is supposed to write the resolved BentoML configuration to a file handle. It currently dumps the BentoMLContainer.config provider object instead of the configuration dictionary:

content = yaml.safe_dump(BentoMLContainer.config)

yaml.safe_dump cannot represent a simple_di Configuration provider, so the call raises RepresenterError every time:

yaml.representer.RepresenterError: ('cannot represent an object',
  Configuration(data={'version': 1, 'api_server': ...}))

Reproduction

import io
import bentoml

buf = io.StringIO()
bentoml.save_config(buf)  # raises RepresenterError

Expected behavior

The resolved configuration dict should be written, e.g. yaml.safe_dump(BentoMLContainer.config.get()), producing a YAML document with the api_server, runners, tracing, monitoring, and version keys.

Environment

• BentoML main @ 517b343b81aeb0b01bbd908e58e53ad9c12ef7eb