port-amd64/57948: ramdisk-zfsroot should be built by default

[campbell+netbsd%mumble.net@localhost]

>Number:         57948
>Category:       port-amd64
>Synopsis:       ramdisk-zfsroot should be built by default
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    port-amd64-maintainer
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Mon Feb 19 17:55:01 +0000 2024
>Originator:     Taylor R Campbell
>Release:        current, 10, 9
>Organization:
The NetBSD Foundramdisk
>Environment:
>Description:
The current instructions for zfs-on-root are much too complicated and require building a ramdisk, which in turn requires building a whole NetBSD distribution, just to try it out:

https://wiki.netbsd.org/root_on_zfs/

The only part that actually requires building anything right now is the ramdisk, and we already have a cgdroot ramdisk built by default.  But the zfsroot ramdisk is similarly small and useful, so we should built it by default too.
>How-To-Repeat:
follow https://wiki.netbsd.org/root_on_zfs/
>Fix:
Yes, please!