[Frontend] Fix Flaky MCP Streaming Test (#32153)

Signed-off-by: Daniel Salib <danielsalib@meta.com>

tests/entrypoints/openai/responses/test_harmony.py

@@ -925,7 +925,7 @@ async def test_mcp_code_interpreter_streaming(client: OpenAI, model_name: str, s
         }
     ]
     input_text = (
-        "Calculate 15 * 32 using python. "
+        "Calculate 123 * 456 using python. "
         "The python interpreter is not stateful and you must print to see the output."
     )