kokkos: bring back deprecated_code variant

[rbberger]

No description provided.

[tpadioleau]

Actually the CMake defaults are to disable 4 and enable 5 in Kokkos 5, https://github.com/kokkos/kokkos/blob/a5d374ba179921b9805008dda06a4b690cfbdd1a/cmake/kokkos_enable_options.cmake#L41-L42. Note that the documentation seems wrong, https://kokkos.org/kokkos-core-wiki/get-started/configuration-guide.html#general-options.

I wonder if giving the control only over the current major version would be enough ? deprecated_code controls Kokkos_ENABLE_DEPRECATED_CODE_X for Kokkos@X ?

[rbberger]

@tpadioleau I'll do whatever you prefer. It was my understanding that people were asking for X-1 deprecated code.

[rbberger]

It would also be informative if Kokkos plans to always have both X and X-1 depreciated code

[rbberger]

@tpadioleau changed the default to match the CMake defaults. I guess we wait until the next WG meeting to decide if we want the simpler variant?

[cedricchevalier19]

During the WG meeting we say we want to keep the logic simple, so using a boolean variant is the group choice.