Add missing stream=True to chat_history_stream.py

[Copilot]

chat_history_stream.py iterates over the response as a stream (event.choices[0].delta.content) but never passes stream=True to client.chat.completions.create(), causing a runtime failure.

response = client.chat.completions.create(
    model=MODEL_NAME,
    messages=messages,
    temperature=0.7,
    stream=True,  # was missing
)

The Spanish translation (spanish/chat_history_stream.py) already had this parameter.

[Pamela Fox (pamelafox)]

Copilot fix the ruff issue

[Copilot]

Copilot fix the ruff issue

Fixed in 31e97f0. Changed class DayOfWeek(str, Enum) to class DayOfWeek(StrEnum) in both structured_outputs_enum.py and spanish/structured_outputs_enum.py to resolve the ruff UP042 errors.