[feat] ghcr image for clang-format

## feat

ghcr image for clang-format

## background

https://github.com/llvm/llvm-project/issues/212670#issuecomment-5113326769

## problem

Currently cannot find a easy way to get clang-format v23

nix provide v22

https://search.nixos.org/packages?channel=unstable&query=llvmPackages_22.clang-tools

nix haven't provide v23

https://search.nixos.org/packages?channel=unstable&query=llvmPackages_23.clang-tools

archlinux provide v22

https://archlinux.org/packages/extra/x86_64/clang/

aur provide v18

https://aur.archlinux.org/packages?O=0&SeB=nd&K=llvm-git&outdated=&SB=p&SO=d&PP=50&submit=Go

## suggestion

ghcr image for clang-format

## additional

per llvm project CLI, per ghcr image

Read the linked LLVM issue and the LLVM project's guidance for its CLI tools, then identify how a GHCR image would be built and published for clang-format v23. Done means a usable GHCR image exists and provides the requested clang-format version through the documented CLI workflow.

Written by the indexing model from the issue text.