Method AlwaysUseNewThreadExecutor

src/babylon/executor.h:243–243

 private:
  AlwaysUseNewThreadExecutor() noexcept = default;
  AlwaysUseNewThreadExecutor(AlwaysUseNewThreadExecutor&&) = delete;
  AlwaysUseNewThreadExecutor(const AlwaysUseNewThreadExecutor&) = delete;
  AlwaysUseNewThreadExecutor& operator=(AlwaysUseNewThreadExecutor&&) = delete;