Use older Union syntax for older python version support

Author: CalebCourier

guardrails/telemetry/common.py

@@ -186,7 +186,7 @@ def recursive_key_operation(
     data: Dict[str, Any] | List[Any] | str,
     operation: Callable[[str], str],
     keys_to_match: List[str] = ["key", "token"],
-) -> Dict[str, Any] | List[Any] | str:
+) -> Optional[Union[Dict[str, Any], List[Any], str]]:
     """Recursively checks if any key in the dictionary or JSON object is
     present in keys_to_match and applies the operation on the corresponding
     value.