Don't enable HWE kernel for ZFS hosts

[exterrestris]

ZFS kernel module and userspace tool versions must match for ZFS send/receive to function correctly:

• syncoid fails in Ubuntu 20.04.2 LTS kernel 5.11.0-25 due to zfs receive -s issue jimsalterjrs/sanoid#665
• Cannot receive incremental stream: kernel modules must be upgraded to receive this stream jimsalterjrs/sanoid#743

Ubuntu seems to have occasional version mismatches for HWE kernels

[exterrestris]

HWE kernel was needed on Ubuntu 20.04 to support Alder Lake, however as 24.04 is now available will upgrade all ZFS hosts to that version