Don't attempt to download locals from S3 bucket (#1669)

Author: RobertLucian

Diff for: pkg/workloads/cortex/lib/client/tensorflow.py

@@ -277,19 +277,20 @@ def _run_inference(self, model_input: Any, model_name: str, model_version: str)
                             self._models.remove_model(model_name, model_version)
 
                         # download model
-                        logger().info(
-                            f"downloading model {model_name} of version {model_version} from the {upstream_model['provider']} upstream"
-                        )
-                        date = self._models.download_model(
-                            upstream_model["provider"],
-                            upstream_model["bucket"],
-                            model_name,
-                            model_version,
-                            upstream_model["path"],
-                        )
-                        if not date:
-                            raise WithBreak
-                        current_upstream_ts = int(date.timestamp())
+                        if model_name not in self._spec_models.get_local_model_names():
+                            logger().info(
+                                f"downloading model {model_name} of version {model_version} from the {upstream_model['provider']} upstream"
+                            )
+                            date = self._models.download_model(
+                                upstream_model["provider"],
+                                upstream_model["bucket"],
+                                model_name,
+                                model_version,
+                                upstream_model["path"],
+                            )
+                            if not date:
+                                raise WithBreak
+                            current_upstream_ts = int(date.timestamp())
 
                     # load model
                     try: