cerebras template update for memory (#792)

# What does this PR do?

- we no longer have meta-reference as memory provider, update cerebras
template


## Test Plan

```
python llama_stack/scripts/distro_codegen.py
```

## Sources

Please link relevant resources if necessary.


## Before submitting

- [ ] This PR fixes a typo or improves the docs (you can dismiss the
other checks if that's the case).
- [ ] Ran pre-commit to handle lint / formatting issues.
- [ ] Read the [contributor
guideline](https://github.com/meta-llama/llama-stack/blob/main/CONTRIBUTING.md),
      Pull Request section?
- [ ] Updated relevant documentation.
- [ ] Wrote necessary unit or integration tests.

llama_stack/templates/cerebras/cerebras.py

@@ -27,7 +27,7 @@ def get_distribution_template() -> DistributionTemplate:
     providers = {
         "inference": ["remote::cerebras"],
         "safety": ["inline::llama-guard"],
-        "memory": ["inline::meta-reference"],
+        "memory": ["inline::faiss", "remote::chromadb", "remote::pgvector"],
         "agents": ["inline::meta-reference"],
         "eval": ["inline::meta-reference"],
         "datasetio": ["remote::huggingface", "inline::localfs"],