🐛 fix(types.py): fix missing return statement in PromptVertex's _built_object_repr method

The _built_object_repr method in the PromptVertex class was missing a return statement, causing it to not return any value. This fix adds the missing return statement to ensure the method returns the correct value.

src/backend/langflow/graph/vertex/types.py

@@ -208,7 +208,7 @@ class PromptVertex(Vertex):
             # with the variables filled in
             return self._built_object.format(**self.artifacts)
         else:
-            super()._built_object_repr()
+            return super()._built_object_repr()
 
 
 class OutputParserVertex(Vertex):