Change CAPTCHA handling to be only on email verification

This simplifies the implementation considerably, and while not providing
ideal UX, it's the most flexible approach.

app/controllers/auth/confirmations_controller.rb

@@ -22,8 +22,6 @@ class Auth::ConfirmationsController < Devise::ConfirmationsController
   end
 
   def show
-    clear_captcha!
-
     old_session_values = session.to_hash
     reset_session
     session.update old_session_values.except('session_id')
@@ -63,10 +61,6 @@ class Auth::ConfirmationsController < Devise::ConfirmationsController
     invite.present? && !invite.max_uses.nil?
   end
 
-  def captcha_context
-    'email-confirmation'
-  end
-
   def set_pack
     use_pack 'auth'
   end

app/controllers/auth/registrations_controller.rb

@@ -2,7 +2,6 @@
 
 class Auth::RegistrationsController < Devise::RegistrationsController
   include RegistrationSpamConcern
-  include CaptchaConcern
 
   layout :determine_layout
 
@@ -16,8 +15,6 @@ class Auth::RegistrationsController < Devise::RegistrationsController
   before_action :require_not_suspended!, only: [:update]
   before_action :set_cache_headers, only: [:edit, :update]
   before_action :set_registration_form_time, only: :new
-  before_action :extend_csp_for_captcha!, only: [:new, :create]
-  before_action :check_captcha!, only: :create
 
   skip_before_action :require_functional!, only: [:edit, :update]
 
@@ -138,23 +135,4 @@ class Auth::RegistrationsController < Devise::RegistrationsController
   def set_cache_headers
     response.headers['Cache-Control'] = 'no-cache, no-store, max-age=0, must-revalidate'
   end
-
-  def sign_up(resource_name, resource)
-    clear_captcha!
-
-    old_session_values = session.to_hash
-    reset_session
-    session.update old_session_values.except('session_id')
-
-    super
-  end
-
-  def check_captcha!
-    super do |error|
-      build_resource(sign_up_params)
-      resource.validate
-      resource.errors.add(:base, error)
-      respond_with resource
-    end
-  end
 end