Mark flaky Windows test for retry (#2344)

* Mark flaky Windows test for retry

test_multi_client_transform_with_filtering occasionally times out on Windows CI during exception formatting in linecache.checkcache(). Add @pytest.mark.flaky with 3 retries.

* Remove unnecessary delay from flaky marker

Author: jlowin

tests/test_mcp_config.py

@@ -636,6 +636,7 @@ def add(a: int, b: int) -> int:
         assert "test_1_transformed_add" not in tools_by_name
 
 
+@pytest.mark.flaky(retries=3)
 async def test_multi_client_transform_with_filtering(tmp_path: Path):
     """
     Tests that tag-based filtering works when using a transforming MCPConfig.