Continues from #13946: adding support for free-threaded Python 3.14t

• Extend test suite with a configuration for python-version: "3.14t"
• Allow the test suite to run when orjson and/or ujson is not installed, cf also 🗑️ Deprecate ORJSONResponse and UJSONResponse #14964 which deprecated ORJSONResponse & UJSONResponse
• Remove orjson & ujson as a standard test dependency
• Add an additional test configuration to test for deprecated ujson/orjson tests (to ensure coverage goes back to 100%)
• Ensure that fastar 0.9.0 is used

Checklist

• Fix issues with orjson & ujson on free-threaded run
• Run orjson & ujson tests in one specific non-free-threaded run
• Fix fastar issue on free-threaded run: https://github.com/DoctorJohn/fastar/releases/tag/v0.9.0
• Fix SQLAlchemy cyextension issues on Ubuntu

Open question

Decided not to do this:

• Bump pydantic-core & strawberry-graphql (and maybe others) to allow running uv-resolution: lowest-direct on 3.14t as well. This will negatively impact other users on older Python versions / older external lib versions.

Merging this PR will not alter performance

✅ 20 untouched benchmarks

_{Comparing svlandeg:feat/314t (1b2934b) with master (25a3697)}

Thanks for picking this up again!

Hm, now stuck on fastar 😕

It looks like they need an update either to declare support for the free-threaded build or simply update to the latest PyO3 version, which does that automatically. I might poke at that today to help you out here.

It looks like they need an update either to declare support for the free-threaded build or simply update to the latest PyO3 version, which does that automatically. I might poke at that today to help you out here.

That would be awesome, thank you so much!

Looks like the Mac and Windows tests aren't picking up fastar 0.9.0.

Looks like the Mac and Windows tests aren't picking up fastar 0.9.0.

It's unclear to me why the 3.14t test on Windows wasn't installing the latest fastar 0.9.0, https://github.com/fastapilabs/fastapi-cloud-cli has it at "fastar >= 0.8.0". Anyway for now I explicitely require 0.9.0 and then that test does succeed 🎉

The Mac test is a different issue: I was running that one with uv-resolution: lowest-direct which means that it tries out the lower bounds of our supported ranges. Here, it crashed for an older version of Pydantic, which is not surprising. Now the only open question is whether we want to bump those lower bounds (which may be annoying for users on older versions of Python & external repos), or just leave them and assume that users running 3.14t will also have updated dependencies 🤷

Ok cool, confirmed that bumping to pydantic >= 2.12.0 and strawberry-graphql >= 0.284.0 allows the test suite to run succesfully with uv-resolution: lowest-direct on Python 3.14t.

Discussed this internally with Sebastián and decided that we don't want to go so far as bumping Pydantic to 2.12+, as it might create issues for users still on older versions. So, I'll remove this test configuration again and then this PR should be ready for review.