[llvm] [workflows] Split pr-code-format into two parts to make it more secure (PR #78216)

[Tom Stellard via llvm-commits]

tstellar wrote:

@nickdesaulniers Yes, I noticed that.  I have a fix here: https://github.com/llvm/llvm-project/pull/80483

You could also fix it in the PR by merging the latest main branch into your PR branch.

https://github.com/llvm/llvm-project/pull/78216