Make clang-format Git hook work in worktrees
Otherwise, commits will be rejected because the hook cannot be found from the workdir root dir (there is only one .git directory in a checkout, but commands are run relative to the worktree root dir).
Otherwise, commits will be rejected because the hook cannot be found from the workdir root dir (there is only one .git directory in a checkout, but commands are run relative to the worktree root dir).