Function always

test/stdexec/algos/consumers/test_sync_wait.cpp:138–144

  template <class T>
  auto always(T t)
  {
    return [t](auto&&...) mutable
    {
      return std::move(t);
    };
  }

  TEST_CASE("sync_wait doesn't accept multi-variant senders", "[consumers][sync_wait]")
  {