Looks line some oneDPL internal aliases are not used in code

[SergeyKopienko]

https://github.com/oneapi-src/oneDPL/blob/fec85a0169b3c62ce8e67663bf8630385f37e7df/include/oneapi/dpl/pstl/execution_impl.h#L99

The next two aliases looks like not used:

template <typename _ExecutionPolicy>
using __collector_t = typename __internal::__policy_traits<::std::decay_t<_ExecutionPolicy>>::__collector_type;

template <typename _ExecutionPolicy>
using __allow_vector = typename __internal::__policy_traits<::std::decay_t<_ExecutionPolicy>>::__allow_vector;