gix-worktree-state nonexclusive checkout sets executable files world-writable

gitoxide is an implementation of git written in Rust. Prior to 0.17.0, gix-worktree-state specifies 0777 permissions when checking out executable files, intending that the umask will restrict them appropriately. But one of the strategies it uses to set permissions is not subject to the umask. This causes files in a repository to be world-writable in some situations. This vulnerability is fixed in 0.17.0.