feat: disable post training in starter but keep the CI test

The default starter distro won't enable post_training by default, to
activate the provider run the distro this env variable
ENABLE_HUGGINGFACE=huggingface

Signed-off-by: Sébastien Han <seb@redhat.com>

llama_stack/templates/starter/run.yaml

@@ -179,7 +179,7 @@ providers:
       sqlite_db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/starter}/trace_store.db
       otel_exporter_otlp_endpoint: ${env.OTEL_EXPORTER_OTLP_ENDPOINT:=}
   post_training:
-  - provider_id: huggingface
+  - provider_id: ${env.ENABLE_HUGGINGFACE:=__disabled__}
     provider_type: inline::huggingface
     config:
       checkpoint_format: huggingface

llama_stack/templates/starter/starter.py

@@ -281,7 +281,7 @@ def get_distribution_template() -> DistributionTemplate:
         config=SentenceTransformersInferenceConfig.sample_run_config(),
     )
     post_training_provider = Provider(
-        provider_id="huggingface",
+        provider_id="${env.ENABLE_HUGGINGFACE:=__disabled__}",
         provider_type="inline::huggingface",
         config=HuggingFacePostTrainingConfig.sample_run_config(f"~/.llama/distributions/{name}"),
     )