fix: Fix serialization error caused by ignored field in ErrorInfo object

- Change `ErrorInfo` class attribute `_repr` to `repr` for consistent serialization
- Update `__repr__` method to return `self.repr` instead of `self._repr`

autogpts/autogpt/autogpt/models/action_history.py

@@ -30,22 +30,22 @@ class ErrorInfo(BaseModel):
     args: tuple
     message: str
     exception_type: str
-    _repr: str
+    repr: str
 
     @staticmethod
     def from_exception(exception: Exception) -> ErrorInfo:
         return ErrorInfo(
             args=exception.args,
             message=getattr(exception, "message", exception.args[0]),
             exception_type=exception.__class__.__name__,
-            _repr=repr(exception),
+            repr=repr(exception),
         )
 
     def __str__(self):
         return repr(self)
 
     def __repr__(self):
-        return self._repr
+        return self.repr
 
 
 class ActionErrorResult(BaseModel):