openai-python v2.48.0 adds None support for cache keys and spend limit APIs

The openai-python client library has released version 2.48.0, introducing support for passing `None` to `prompt_cache_key` and `safety_identifier` for enhanced caching flexibility. It also adds support for `spend_limit` administrative APIs, beneficial for managing resource allocation. These updates are relevant for developers using the Python client to interact with OpenAI services, particularly those managing caching or administrative functions.

• →accept None for prompt_cache_key/safety_identifier
• →add support for spend_limit admin apis