fix docstring

Author: ShreyeshArangath

python/datafusion/plan.py

@@ -320,8 +320,8 @@ def labels(self) -> dict[str, str]:
 
         Labels provide additional context for a metric.  For example::
 
-            >>> metric.labels()
-            {'output_type': 'final'}
+            metric.labels()
+            # {'output_type': 'final'}
         """
         return self._raw.labels()