Add :weight as an allowed serializable field in app/controllers/boards/issues_controller.rb

Signed-off-by: Rémy Coutable <remy@rymai.me>

app/controllers/boards/issues_controller.rb

@@ -94,7 +94,7 @@ module Boards
 
     def serialize_as_json(resource)
       resource.as_json(
-        only: [:id, :iid, :project_id, :title, :confidential, :due_date, :relative_position],
+        only: [:id, :iid, :project_id, :title, :confidential, :due_date, :relative_position, :weight],
         labels: true,
         issue_endpoints: true,
         include_full_project_path: board.group_board?,