Docs include stale OFED info

[MoteHue]

We no longer publish images with OFED built in. The upgrade docs still reference these, so should be updated to correct that. Would also be good to point to how to build an image with OFED yourself here instead.

Link: https://github.com/stackhpc/ansible-slurm-appliance/blob/0aec76cebc5974276f2b23b8c869a4142d2b908a/docs/upgrades.md?plain=1#L57C1-L59C158

[sjpb]

Should probably remove OFED entirely now we are using DOCA in places

[priteau]

Please don't remove OFED. The role still works fine and is required. For example WEKA doesn't officially support DOCA yet.

[sjpb]

Ah right, useful. FWIW a buld using the ofed role failed, I think the LTS version we are using is no longer the lts version or something ...

[sjpb]

So, should probably warn ofed is not "supported", in the sense that we don't even test it builds in CI.