format.sh does not format correctly enough for check.sh

[H-Huang]

I noticed for many of my PRs after running ./format.sh, it still does not pass the checks in ./check.sh. This causes the PR to fail in the lint check in CI. The reason is because ./format.sh does not satisfy all the requirements in ./check.sh, check.sh is using ufmt and format is using some packages like autoflake or isort that do not work completely:

https://github.com/pytorch/PiPPy/blob/f2e605d045cdc64cac31e2dd99a01706eb638a16/format.sh#L40-L52

I wonder if we can just turn to an all in one solution like ruff (https://github.com/astral-sh/ruff) to act as both our linter, formatter, and checker.