F37: CHANGE: BIOS boot.iso with GRUB2

[dustymabe]

For the proposed Fedora 37 changes we decided to discuss further the following change:

• BIOS boot.iso with GRUB2
  • Modify lorax-generic-templates to use GRUB2 when booting the boot.iso on BIOS systems, instead of syslinux. Upstream syslinux development is dead, and the Fedora maintainer would like to drop the package from the distribution. GRUB2 works as a replacement in most situations and continues to have upstream support.
  • Tracking bug: #2092065
  • NOTES: LB: I think we'd like to do this move too, in coreos-assembler and FCOS-config. Also consider what happens for RHCOS.

[dustymabe]

My understanding is that the ultimate goal (maybe not in F37, but later) is to remove maintenance of syslinux in Fedora. If we could change our ISO BIOS boot workflow to use GRUB2 as well, then I think we'd be shedding our syslinux dependency too.

We'd also need to think of the implications of this with respect to RHCOS and when we'd be able to make a similar change there.