Reverted change that avoided serializing logprobs

ldp/graph/ops.py

@@ -61,9 +61,7 @@ def to_dict(self) -> dict[str, Any]:
             "op_name": self.op_name,
             "op_class_name": self.op_class_name,
             "value": value_dump,
-            # NOTE: logprob is not a OpResult attribute. So this breaks serialization
-            #
-            # "logprob": self.logprob,
+            "logprob": self.logprob,
         }
 
     @classmethod