Reduce hard coding of LOCAL_DOMAIN env value throughout tests (#35025)

spec/system/captcha_spec.rb

@@ -31,7 +31,7 @@ RSpec.describe 'email confirmation flow when captcha is enabled' do
 
       # It presents a page with a link to the app callback
       expect(page)
-        .to have_content(I18n.t('auth.confirmations.registration_complete', domain: 'cb6e6126.ngrok.io'))
+        .to have_content(I18n.t('auth.confirmations.registration_complete', domain: Rails.configuration.x.local_domain))
         .and have_link(I18n.t('auth.confirmations.clicking_this_link'), href: client_app.confirmation_redirect_uri)
     end
   end

spec/system/redirections_spec.rb

@@ -31,6 +31,6 @@ RSpec.describe 'redirection confirmations' do
   end
 
   def redirect_title
-    I18n.t('redirects.title', instance: 'cb6e6126.ngrok.io')
+    I18n.t('redirects.title', instance: Rails.configuration.x.local_domain)
   end
 end