Fix double-quoted string in get_message method

Author: mohit-singlestore

singlestoredb/management/inference_api.py

@@ -86,7 +86,7 @@ def get_message(self) -> str:
             Message describing the operation result
 
         """
-        return f"Model is {self.status}"
+        return f'Model is {self.status}'
 
     def __str__(self) -> str:
         """Return string representation."""