Incorrect __future class implementation

[SergeyKopienko]

oneDPL/include/oneapi/dpl/pstl/hetero/dpcpp/parallel_backend_sycl_utils.h

Line 700 in e2e6ffd

__future(_Event __e, _Args... __args) : std::tuple<_Args...>(__args...), __my_event(__e) {}

As we may see at https://en.cppreference.com/w/cpp/thread/future/future and https://en.cppreference.com/w/cpp/thread/future/operator%3D, the std::future implementation has deleted copy-constructor and copy-assignment : only move-constructor and move-assignment supported.

I believe we forgot to implement these restrictions in oneDPL implementation of __future.