enable ufmt for torch/testing/*.py (#89525)
I've tried to soft-enforce this manually already, albeit with a line length of 120. This just adds it to the CI. Note that this only applies to `torch/testing/*.py` and thus everything under `torch/testing/_internal/**/*` is *not* affected.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/89525
Approved by: https://github.com/kit1980
