Remove duplicated api endpoint already existed in CE

ee/lib/ee/api/boards.rb

@@ -18,18 +18,6 @@ module EE
       end
       resource :projects, requirements: ::API::API::PROJECT_ENDPOINT_REQUIREMENTS do
         segment ':id/boards' do
-          desc 'Get all project boards' do
-            detail 'This feature was introduced in 8.13'
-            success ::API::Entities::Board
-          end
-          params do
-            use :pagination
-          end
-          get '/' do
-            authorize!(:read_board, user_project)
-            present paginate(board_parent.boards), with: ::API::Entities::Board
-          end
-
           desc 'Create a project board' do
             detail 'This feature was introduced in 10.4'
             success ::API::Entities::Board