litellm passes untrusted data to `eval` function without sanitization

A remote code execution (RCE) vulnerability exists in the berriai/litellm project due to improper control of the generation of code when using the `eval` function unsafely in the `litellm.get_secret()` method. Specifically, when the server utilizes Google KMS, untrusted data is passed to the `eval` function without any sanitization. Attackers can exploit this vulnerability by injecting malicious values into environment variables through the `/config/update` endpoint, which allows for the update of settings in `proxy_server_config.yaml`.