Add test stage for ROCm configuration

[msimberg]

This won't work yet...

• [ ] Add testing also for stdexec configuration

[msimberg]

cscs-ci run

[msimberg]

cscs-ci run

[msimberg]

cscs-ci run

[msimberg]

cscs-ci run

[msimberg]

cscs-ci run

[msimberg]

cscs-ci run

[msimberg]

This is currently failing due to a buggy Cray MPICH used by sarus. The buggy MPICH leads to the all but the first MPI executable failing to initialize MPI in a SLURM job. Only the CUDA-aware MPICH seems to be buggy. This is waiting for a change to sarus which will use a non-CUDA-aware MPICH by default, and allow choosing the CUDA-aware one explicitly if needed.

[msimberg]

I think by now this is so out of date that it's easier to start over once we actually have access to AMD GPUs for CI again, so I'll close this.