Apply ufmt linter to all py files under test/onnx (#81335)
Same as https://github.com/pytorch/pytorch/pull/81285 but for `test/onnx`. The merge conflicts in `linrunner.toml` is expected. I will resolve them depending on the merge order of the PR
Pull Request resolved: https://github.com/pytorch/pytorch/pull/81335
Approved by: https://github.com/BowenBao, https://github.com/kit1980
