Enable JS on 2FA page to catch validation errors

Enables JavaScript on specs which is responsible for triggering
HTML5 form validation on 2FA page in case the code provided
is invalid.

spec/features/users/login_spec.rb

@@ -152,7 +152,7 @@ describe 'Login' do
     end
   end
 
-  describe 'with two-factor authentication' do
+  describe 'with two-factor authentication', :js do
     def enter_code(code)
       fill_in 'user_otp_attempt', with: code
       click_button 'Verify code'

spec/support/helpers/user_login_helper.rb

@@ -13,7 +13,7 @@ module UserLoginHelper
 
   def ensure_tab_pane_counts
     tabs_count = page.all('[role="tab"]').size
-    expect(page).to have_selector('[role="tabpanel"]', count: tabs_count)
+    expect(page).to have_selector('[role="tabpanel"]', visible: :all, count: tabs_count)
   end
 
   def ensure_one_active_tab