Build: Remove grunt concat task its no longer used

This task was only used to create the combined js file for sizer
and for creating the combined files for the NPM package. The
npm package is no longer maintained so there is no need for this any more.

Gruntfile.js

@@ -24,29 +24,6 @@ var
 
 	allI18nFiles = expandFiles( "ui/i18n/*.js" ),
 
-	cssFiles = [
-		"core",
-		"accordion",
-		"autocomplete",
-		"button",
-		"datepicker",
-		"dialog",
-		"draggable",
-		"menu",
-		"progressbar",
-		"resizable",
-		"selectable",
-		"selectmenu",
-		"sortable",
-		"slider",
-		"spinner",
-		"tabs",
-		"tooltip",
-		"theme"
-	].map(function( component ) {
-		return "themes/base/" + component + ".css";
-	}),
-
 	// minified files
 	minify = {
 		options: {
@@ -149,25 +126,6 @@ grunt.initConfig({
 		dist: "<%= pkg.name %>-<%= pkg.version %>"
 	},
 	compare_size: compareFiles,
-	concat: {
-		i18n: {
-			options: {
-				banner: createBanner( allI18nFiles )
-			},
-			src: allI18nFiles,
-			dest: "dist/i18n/jquery-ui-i18n.js"
-		},
-		css: {
-			options: {
-				banner: createBanner( cssFiles ),
-				stripBanners: {
-					block: true
-				}
-			},
-			src: cssFiles,
-			dest: "dist/jquery-ui.css"
-		}
-	},
 	requirejs: {
 		js: {
 			options: {