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.ime.js

@@ -215,9 +215,9 @@
 			return;
 		}
 		// Extend the ime preference system
-		$.extend( $.ime.preferences, ulsIMEPreferences );
+		Object.assign( $.ime.preferences, ulsIMEPreferences );
 		// MediaWiki specific overrides for jquery.ime
-		$.extend( $.ime.defaults, {
+		Object.assign( $.ime.defaults, {
 			imePath: mwImeRulesPath
 		} );