Remove indirection to set current host for ActiveStorage

We no longer support Rails v5.2, so there's no need to support the old
way [1]. As we only need to include a Rails module, there's neither the need
to go through a custom module.

[1] - rails/rails@e33c3cd

api/app/controllers/spree/api/base_controller.rb

@@ -10,7 +10,7 @@ class BaseController < ActionController::Base
  protect_from_forgery unless: -> { request.format.json? }
 
  include CanCan::ControllerAdditions
- include Spree::Core::ControllerHelpers::CurrentHost
+ include ActiveStorage::SetCurrent
  include Spree::Core::ControllerHelpers::Store
  include Spree::Core::ControllerHelpers::Pricing
  include Spree::Core::ControllerHelpers::StrongParameters

core/app/controllers/spree/base_controller.rb

@@ -4,7 +4,7 @@
 require_dependency 'spree/core/controller_helpers/strong_parameters'
 
 class Spree::BaseController < ApplicationController
- include Spree::Core::ControllerHelpers::CurrentHost
+ include ActiveStorage::SetCurrent
  include Spree::Core::ControllerHelpers::Auth
  include Spree::Core::ControllerHelpers::Common
  include Spree::Core::ControllerHelpers::PaymentParameters

core/lib/spree/rails_compatibility.rb

@@ -72,23 +72,6 @@ def self.default_taxon_attachment_module
  end
  end
 
- # Set current host for ActiveStorage in a controller
- #
- # Changed from `#host` to including a module in Rails 6
- #
- # See https://github.com/rails/rails/commit/e33c3cd8ccbecaca6c6af0438956431b02cb3fb2
- #
- # TODO: Remove when deprecating Rails 5.2
- def self.active_storage_set_current(controller)
- if version_gte?('6')
- controller.include ActiveStorage::SetCurrent
- else
- controller.before_action do
- ActiveStorage::Current.host = request.base_url
- end
- end
- end
-
  # Set current host for ActiveStorage
  #
  # Changed from `#host` to `#url_options` on Rails 7