fastapi use orjson as default serializer ORJSONResponse

I can be as simple as: app = FastAPI(default_response_class=ORJSONResponse)
Or more robust：

from fastapi import FastAPI
from fastapi.responses import ORJSONResponse

try:
    import orjson
except ImportError:
    extra_app_kwargs: dict[str, Any] = {}
else:
    logger.info(f"Use orjson {orjson.__version__} to speed up JSON serializer")
    extra_app_kwargs = {"default_response_class": ORJSONResponse}

app = FastAPI(title='这是标题', **extra_app_kwargs)