Fix pyright warnings in test_stdio_cm.py

Author: LionNatsu

tests/client/test_stdio_cm.py

@@ -3,14 +3,10 @@
 from mcp import StdioServerParameters
 from mcp.client.stdio import stdio_client
 
-MCP_SERVER = {
-    "command": "tee",
-}
-
 
 @pytest.mark.anyio
 async def test_context_manager_exiting():
-    async with stdio_client(StdioServerParameters(**MCP_SERVER)) as (
+    async with stdio_client(StdioServerParameters(command="tee")) as (
         read_stream,
         write_stream,
     ):