Avoid N+1 queries in rendering project meta

src/api/app/views/models/_project.xml.builder

@@ -19,7 +19,7 @@ xml.project(project_attributes) do
 
   my_model.render_relationships(xml)
 
-  repos = my_model.repositories.not_remote.sort { |a, b| b.name <=> a.name }
+  repos = my_model.repositories.preload(:download_repositories, :release_targets, :hostsystem, path_elements: :link).not_remote.sort { |a, b| b.name <=> a.name }
   FlagHelper.render(my_model, xml)
 
   repos.each do |repo|
@@ -65,10 +65,11 @@ xml.project(project_attributes) do
     end
   end
 
-  unless MaintainedProject.where(maintenance_project_id: my_model.id).empty?
+  maintained_projects = my_model.maintained_project_names
+  unless maintained_projects.empty?
     xml.maintenance do |maintenance|
-      MaintainedProject.where(maintenance_project_id: my_model.id).each do |mp|
-        maintenance.maintains(project: mp.project.name)
+      maintained_projects.each do |mp|
+        maintenance.maintains(project: mp)
       end
     end
   end