fix: simplify stream cleanup type to avoid line length issues

- Use list[Any] for streams_to_cleanup to avoid very long type annotation

- Fixes ruff E501 line too long error

Author: dgenio

tests/shared/test_proxy.py

@@ -1,6 +1,7 @@
 """Tests for the MCP proxy pattern."""
 
 from collections.abc import Callable
+from typing import Any
 
 import anyio
 import pytest
@@ -21,7 +22,7 @@
 @pytest.fixture
 async def create_streams() -> Callable[[], StreamsFixtureReturn]:
     """Helper fixture to create memory streams for testing with proper cleanup."""
-    streams_to_cleanup: list[MemoryObjectSendStream[SessionMessage | Exception] | MemoryObjectReceiveStream[SessionMessage | Exception] | MemoryObjectSendStream[SessionMessage] | MemoryObjectReceiveStream[SessionMessage]] = []
+    streams_to_cleanup: list[Any] = []
 
     def _create() -> StreamsFixtureReturn:
         client_read_writer, client_read = anyio.create_memory_object_stream[SessionMessage | Exception](10)