Deepseek provider isn't exposing caching values in usage

[matannahmani]

Description

run any request you will see usage is missing the fields that deepseek mention (https://api-docs.deepseek.com/news/news0802)

Monitoring Cache Hits
Two new fields in the API response's usage section help users monitor cache performance:

prompt_cache_hit_tokens：Number of tokens from the input that were served from the cache ($0.014 per million tokens)
prompt_cache_miss_tokens: Number of tokens from the input that were not served from the cache ($0.14 per million tokens)

this is most likely related to open-ai compatible package which isn't spreading the usage record.

Code example

No response

AI provider

No response

Additional context

No response

[shaper]

Hi, thanks for the report, looking into support for this.