rocmPackages: drop engineering sample only ISAs

[mschwaig]

Issue description

ROCm builds take a long time and their outputs are quite large. It was pointed out in #298388 (comment) that there are some engineering sample only ISAs for MI300, which we could drop.

[...]
If you need to cut down on size, you could consider dropping gfx940 and gfx941. Those ISAs were used for early engineering samples, but all final MI300 hardware uses the gfx942 ISA.

I think we should verify this info, check what other distributions are doing and test out what this approach gets us in terms of size and build times.

@ulrikstrid suggested this might make sense to do, even if we compress the output of ROCm.