build: Updating npm dependencies

* eslint-config-wikimedia: 0.28.0 → 0.28.2
  The following rules are failing and were disabled:
  * resources/js:
    * es-x/no-object-assign

* grunt-stylelint: 0.20.0 → 0.20.1
* stylelint-config-wikimedia: 0.17.1 → 0.17.2

Change-Id: I93fa42275d02c006a0dcb2be6fc152c5a0daaa15

resources/js/ext.uls.mediawiki.js

@@ -21,7 +21,7 @@
 	'use strict';
 
 	// MediaWiki overrides for ULS defaults
-	$.fn.uls.defaults = $.extend( $.fn.uls.defaults, {
+	$.fn.uls.defaults = Object.assign( $.fn.uls.defaults, {
 		languages: mw.config.get( 'wgULSLanguages' ) || {},
 		searchAPI: mw.util.wikiScript( 'api' ) + '?action=languagesearch&format=json&formatversion=2'
 	} );