don't reload the merge request in render_approvals_json

it's already been done in the relevant service

app/controllers/projects/merge_requests_controller.rb

@@ -519,7 +519,7 @@ class Projects::MergeRequestsController < Projects::ApplicationController
   def render_approvals_json
     respond_to do |format|
       format.json do
-        entity = API::Entities::MergeRequestApprovals.new(@merge_request.reload, current_user: current_user)
+        entity = API::Entities::MergeRequestApprovals.new(@merge_request, current_user: current_user)
         render json: entity
       end
     end