Exclude orjson from dependencies in PyPy environments

[rkrell]

fastapi 0.111.0 could not be built in a PyPy venv due to a officially defined incompatibility of orjson to PyPy. This changes makes fastapi usable again in PyPy.

Resolves discussion #11659.

[tiangolo]

📝 Docs preview for commit 8252dc9 at: https://3880f3c4.fastapitiangolo.pages.dev

[tiangolo]

📝 Docs preview for commit 9426427 at: https://d55701a9.fastapitiangolo.pages.dev

[tiangolo]

Thank you! ☕

Given this and another report, I decided to remove orjson and ujson from the default dependencies. They are still included with pip install "fastapi[all]" but not with pip install fastapi. (#11842)

That change is now available in FastAPI 0.111.1. 🚀

Thanks for letting me know and for the fix PR! 🍰