Fix Style/OpenStructUse offenses by using `Struct`

Changelog: other

.rubocop_todo/style/open_struct_use.yml

 ---
 Style/OpenStructUse:
   Exclude:
-  - app/helpers/application_settings_helper.rb
   - ee/spec/features/projects/new_project_spec.rb
   - ee/spec/finders/template_finder_spec.rb
   - ee/spec/helpers/ee/blob_helper_spec.rb

app/helpers/application_settings_helper.rb

@@ -37,9 +37,15 @@ module ApplicationSettingsHelper
   end
 
   def storage_weights
-    Gitlab.config.repositories.storages.keys.each_with_object(OpenStruct.new) do |storage, weights|
-      weights[storage.to_sym] = @application_setting.repository_storages_weighted[storage] || 0
+    # Instead of using a `Struct` we could wrap this into an object.
+    # See https://gitlab.com/gitlab-org/gitlab/-/issues/358419
+    weights = Struct.new(*Gitlab.config.repositories.storages.keys.map(&:to_sym))
+
+    values = Gitlab.config.repositories.storages.keys.map do |storage|
+      @application_setting.repository_storages_weighted[storage] || 0
     end
+
+    weights.new(*values)
   end
 
   def all_protocols_enabled?