Function re_build_tools::git::git_path

fn git_path(path: &str) -> Result<PathBuf>

From https://git-scm.com/docs/git-rev-parse:

Resolve $GIT_DIR/<path> and takes other path relocation variables such as $GIT_OBJECT_DIRECTORY, $GIT_INDEX_FILE…​ into account. For example, if $GIT_OBJECT_DIRECTORY is set to /foo/bar then git rev-parse --git-path objects/abc returns /foo/bar/abc.