careful promise to instantiate replacement

Signed-off-by: dafnapension <dafnashein@yahoo.com>

src/unitxt/artifact.py

@@ -270,7 +270,7 @@ def prepare(self):
                 hasattr(self, "__replacing_artifact__")
                 and self.__replacing_artifact__ is not None
             ):
-                message += f"Its replacement, of type {self.__replacing_artifact__}, is instantiated instead."
+                message += f"Its replacement, of type {self.__replacing_artifact__}, is to be instantiated instead."
             warnings.warn(message, DeprecationWarning, stacklevel=2)
 
     def verify(self):