### Check for existing issues

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

### What happened?

**What happened:** When running the LiteLLM Proxy with multiple workers (`--num_workers 4`) and a Redis cache configured, deleting a model added via API (`/model/new`) via the `/model/delete` API does not invalidate the local in-memory cache of the *other* workers.

The worker handling the delete request successfully removes the model from the Postgres DB and its own RAM. However, it seems no Pub/Sub broadcast is sent (or received) via Redis to tell the other workers to drop the model. As a result API calls to `/model/info` start "flapping" randomly, showing the deleted model or hiding it, depending on which worker handles the request.

*Note: This was tested with both Valkey 8.0.1 and official Redis 8.6.3. The issue persists regardless of the Redis distribution.*

**What did you expect to happen?** When `/model/delete` is called, the proxy should broadcast a cache invalidation event via Redis to all other Uvicorn workers immediately, purging the model from all local memories so the Proxy state remains consistent.

### Steps to Reproduce

**1. …