[llvm] code-format: Improve the code-format-helper to be able to run as a git hook (PR #73957)

[Aiden Grossman via llvm-commits]

https://github.com/boomanaiden154 commented:

No major issues on my side, a couple small python nits.

Can't really comment on the full hooks integration as I'm not very familiar with how they work/any nuances/footguns there.

It would be nice to figure out unit/integration testing for this to make changes easier/prevent regressions, but given the interaction with the GH API it would require mocking and some engineering effort that might not be worth it.

https://github.com/llvm/llvm-project/pull/73957