Merge branch '213728-remove-unused-notify_post_receive-endpoint' into 'master'

Drop unused notify_post_receive endpoint

See merge request gitlab-org/gitlab!29241

lib/api/internal/base.rb

@@ -203,10 +203,6 @@ module API
           { reference_counter_increased: reference_counter_increased }
         end
 
-        post '/notify_post_receive' do
-          status 200
-        end
-
         post '/post_receive' do
           status 200