Transient failure in spec/services/todo_service_spec.rb

As seen in https://gitlab.com/gitlab-org/gitlab-ee/builds/10558967:

  1) TodoService Merge Requests #new_merge_request when the merge request has approvers creates a todo for each valid mentioned user
     Failure/Error: expect(Todo.where(attributes).count).to eq 1

       expected: 1
            got: 0

       (compared using ==)
     # ./spec/services/todo_service_spec.rb:845:in `should_create_todo'
     # ./spec/services/todo_service_spec.rb:527:in `block (5 levels) in <top (required)>'

Finished in 53 minutes 6 seconds (files took 46.42 seconds to load)
1257 examples, 1 failure

Failed examples:

rspec ./spec/services/todo_service_spec.rb:526 # TodoService Merge Requests #new_merge_request when the merge request has approvers creates a todo for each valid mentioned user