[serve] logging_config specified in serve.run is not propagated cluster-wide

[paul-twelvelabs]

Description

Specifying logging_config in serve.run(..., logging_config={...}) does not configure logging for the cluster, as is expected. This is because we don't propagate logging_config to .serve_start(...) here:

https://github.com/ray-project/ray/blob/master/python/ray/serve/api.py#L475-L477

A simple workaround for now is,

logging_config = {"log_level": "..."}
serve.start(logging_config=logging_config)
serve.run(logging_config=logging_config)

Use case

This issue arose when trying to configure Serve logging holistically for tests.