[llvm] [Github] Fetch all commits in PR for code formatting checks (PR #69766)

[Aiden Grossman via llvm-commits]

boomanaiden154 wrote:

Well that didn't last long.

This was causing fetch failures. Need to do some more debugging and figure out why. Even with debug logging, the error messages are incredibly unhelpful.

https://github.com/llvm/llvm-project/actions/runs/6697812983/job/18198489209

https://github.com/llvm/llvm-project/pull/69766