fix: namespace prefixing

Author: mrkaye97

hatchet_sdk/loader.py

@@ -88,6 +88,9 @@ def validate_token(cls, token: str) -> str:
     @field_validator("namespace", mode="after")
     @classmethod
     def validate_namespace(cls, namespace: str) -> str:
+        if not namespace:
+            return ""
+
         if not namespace.endswith("_"):
             namespace = f"{namespace}_"