Function list_files_walk

fn list_files_walk(
    path: &Path,
    ret: &mut Vec<PathBuf>,
    is_root: bool,
    filter: &dyn Fn(&Path, bool) -> bool,
    gctx: &GlobalContext,
) -> CargoResult<()>

Lists files relevant to building this package inside this source by walking the filesystem from the package root path.

This is a fallback for list_files_gix when the package is not tracked under a Git repository.