Create is_finetuning property in TrainingMixin

arkindex_worker/worker/training.py

@@ -81,6 +81,10 @@ class TrainingMixin:
 
     model_version = None
 
+    @property
+    def is_finetuning(self) -> bool:
+        return bool(self.model_version_id)
+
     @skip_if_read_only
     def publish_model_version(
         self,