fix(isolate): don't use dataclass for serialization errors (#131)

src/isolate/connections/common.py

@@ -2,7 +2,6 @@
 
 import importlib
 import os
-from dataclasses import dataclass
 from typing import TYPE_CHECKING, Any, cast
 
 from tblib import Traceback, TracebackParseError
@@ -21,11 +20,10 @@ def dumps(self, obj: Any) -> bytes: ...
 AGENT_SIGNATURE = "IS_ISOLATE_AGENT"
 
 
-@dataclass
 class BaseSerializationError(IsolateException):
     """An error that happened during the serialization process."""
 
-    message: str
+    pass
 
 
 class SerializationError(BaseSerializationError):