ENGCOM-3522: chore: remove old code for IE9 #19331

 - Merge Pull Request #19331 from DanielRuf/magento2:chore/lib-varien-remove-ie9-code
 - Merged commits:
   1. 486aead

lib/web/varien/js.js

@@ -607,17 +607,11 @@ if (!("console" in window) || !("firebug" in console))
  * @example fireEvent($('my-input', 'click'));
  */
 function fireEvent(element, event) {
-    if (document.createEvent) {
-        // dispatch for all browsers except IE before version 9
-        var evt = document.createEvent('HTMLEvents');
+    // dispatch event
+    var evt = document.createEvent('HTMLEvents');
 
-        evt.initEvent(event, true, true); // event type, bubbling, cancelable
-        return element.dispatchEvent(evt);
-    }
-    // dispatch for IE before version 9
-    var evt = document.createEventObject();
-
-    return element.fireEvent('on' + event, evt);
+    evt.initEvent(event, true, true); // event type, bubbling, cancelable
+    return element.dispatchEvent(evt);
 
 }