Anthropic cache setting not honored

[rxgrant]

config.assistant.request.cache

Cache breakpoint is hardcoded to
async_anthropic::types::CacheControl::default(), which is the
standard 5-minute ephemeral cache.

[JeanMertz]

Correct. I think I mentioned this somewhere before. I have a local conversation that discusses wiring this up, let me dig it up and see what the conclusion was on how easy it is to wire this up, I don't think it'll take a lot of work, AFAIK we have all the pieces in place already, the config layer is there, and the providers can read the current config, so all we're missing is the translation from the config to the final cache values for the Anthropic provider.