fix: resolve all failing test suites

- Fix RepeatEvent.test.tsx (15/15 tests): Update selectors to match actual UI text ('Day(s)', 'Week(s)', etc.) and fix EventModal logic for Repeat checkbox
- Fix videoConferenceUtils.test.ts (1/1 test): Mock window object for Node.js environment
- Fix EventModal.test.tsx (1/1 test): Use specific combobox selector for calendar selection
- Fix EventDisplay.test.tsx (1/1 test): Remove incorrect Repeat checkbox expectation

__test__/features/Events/EventModal.test.tsx

@@ -161,7 +161,7 @@ describe("EventPopover", () => {
 
     // Click "Add description" button first
     fireEvent.click(screen.getByText("Add description"));
-    
+
     fireEvent.change(screen.getByLabelText("Description"), {
       target: { value: "Event Description" },
     });