Remove broken dead code branch

The StripeSCA method is forwarding all missing methods to the provider
gateway. The ActiveMerchant gateway used to be decorated by our code and
that's how this code may have worked one day. But we removed the
decorator years ago:

- 549610bc35

A bit later we found that refunds are broken with Stripe:

- https://github.com/openfoodfoundation/openfoodnetwork/issues/12843

This commit could potentiall fix that, I guess? I haven't tested that.
It's a rare use case and not the aim of this work.

app/models/spree/gateway/stripe_sca.rb

@@ -106,6 +106,12 @@ module Spree
         provider.refund(money, payment_intent_id, gateway_options)
       end
 
+      # NOTE: this method is required by Spree::Payment::Processing
+      def refund(money, payment_intent_id, gateway_options)
+        gateway_options[:stripe_account] = stripe_account_id
+        provider.refund(money, payment_intent_id, gateway_options)
+      end
+
       def create_profile(payment)
         return unless payment.source.gateway_customer_profile_id.nil?
 

app/models/spree/payment/processing.rb

@@ -107,20 +107,11 @@ module Spree
 
           refund_amount = calculate_refund_amount(refund_amount)
 
-          response = if payment_method.payment_profiles_supported?
-                       payment_method.refund(
-                         (refund_amount * 100).round,
-                         source,
-                         response_code,
-                         gateway_options
-                       )
-                     else
-                       payment_method.refund(
-                         (refund_amount * 100).round,
-                         response_code,
-                         gateway_options
-                       )
-                     end
+          response = payment_method.refund(
+            (refund_amount * 100).round,
+            response_code,
+            gateway_options
+          )
 
           record_response(response)