ncdu: add updateScript

pkgs/by-name/nc/ncdu/package.nix

···
   versionCheckProgramArg = "--version";
   doInstallCheck = true;
 
+  passthru.updateScript = ./update.sh;
+
   meta = {
     homepage = "https://dev.yorhel.nl/ncdu";
     description = "Disk usage analyzer with an ncurses interface";

pkgs/by-name/nc/ncdu/update.sh

···
+#!/usr/bin/env nix-shell
+#!nix-shell -i bash -p common-updater-scripts coreutils gnused nix-update
+
+version=$(list-git-tags --url=https://g.blicky.net/ncdu.git | tail -1 | sed 's/^v//')
+nix-update --version="$version" ncdu