fix: tests failing as changed tab open handler from mousedown to click

Author: devvaannsh

test/spec/Extn-Tabbar-integ-test.js

@@ -1193,7 +1193,7 @@ define(function (require, exports, module) {
                 async function clickTabAndVerify(filePath, description) {
                     const $tab = getTab(filePath);
                     expect($tab.length).toBe(1);
-                    $tab.trigger("mousedown");
+                    $tab.trigger("click");
 
                     // Wait for the file to become active
                     await awaitsFor(