small fix for old python

Author: vhaldemar

src/yandex_cloud_ml_sdk/_tools/tool.py

@@ -51,7 +51,7 @@ def _from_upper_proto(cls, proto: ProtoToolTypeT, sdk: SDKType) -> BaseTool:
         raise NotImplementedError('tools other then search_index and function are not supported in this SDK version')
 
 
-ProtoFunctionTool = Union[ProtoCompletionsFunctionTool | ProtoAssistantsFunctionTool]
+ProtoFunctionTool = Union[ProtoCompletionsFunctionTool, ProtoAssistantsFunctionTool]
 
 
 @dataclass(frozen=True)