### Check for existing issues

- [x] I have searched the existing issues and checked that my issue is not a duplicate.

### What happened?

Under sustained load, one of our proxy pods got a Redis connection into a bad state (repeated "No connection available"). We expected the circuit breaker in `RedisCache` (`_redis_circuit_breaker_guard`, `REDIS_CIRCUIT_BREAKER_ENABLED`/`_FAILURE_THRESHOLD`/`_RECOVERY_TIMEOUT`) to open after a few consecutive failures and fast-fail for a bit. Instead it never opened — the same error just logged forever at the request rate (~80-95/sec, sustained for 9+ minutes straight in two separate load tests).

Root cause: `async_set_cache` and `async_set_cache_pipeline` in `litellm/caching/redis_cache.py` both catch the Redis exception, log it, and return without re-raising. They're both decorated with `@_redis_circuit_breaker_guard`, but the guard's own `try/except` only calls `record_failure()` if the wrapped method actually raises. Since these two swallow the exception internally, the guard sees every call as a success and calls `record_success()` instead — resetting the failure counter every time. The breaker can never open for these two methods, no matte…