upgreade sse-starlette 2.3.5

Author: Hoa Lam

examples/servers/simple-tool/mcp_simple_tool/server.py

@@ -64,6 +64,7 @@ async def list_tools() -> list[types.Tool]:
         from starlette.routing import Mount, Route
 
         sse = SseServerTransport("/messages/")
+
         async def handle_sse(request):
             async with sse.connect_sse(
                 request.scope, request.receive, request._send