[llvm] [GitHub][workflows] Use latest clang-format version 18.1.1 (PR #85502)

[Aiden Grossman via llvm-commits]

boomanaiden154 wrote:

I've reverted this for now as I think it needs more discussion. https://discourse.llvm.org/t/rfc-clang-format-all-the-things/76614 is probably the most recent discussion on this, and the consensus there seems to be that we should be conservative with version upgrades due to churn.

Unless there's a specific bug fix/feature that landed in `clang-format` that is important for in-tree use, I think we should hold off on this for now until we have a better specified project-wide policy on what to do with bumping the formatter version. If there's a compelling reason to go forward with this though, I'm not opposed to relanding. I think upgrading just to upgrade doesn't make a lot of sense currently though given the lack of project-wide policy/discussion on this topic.

https://github.com/llvm/llvm-project/pull/85502