[LDWG][FBSD_LDWG] pkgbase: multiple upgrades (with and without pkg 2.0)

When pkgbase was discussed during yesterday's meeting, in the side chat 
I mentioned a plea to test multiple upgrades. For example: 14.1 to 14.2 
then 14.2 to 15.0-CURRENT.

Yesterday's mention was partly a follow-up to last month's 
<https://lists.freebsd.org/archives/freebsd-pkgbase/2024-December/000487.html>. 


I do have a destructible boot environment set aside for cloning and 
testing, however (without going into too much detail) we really need a 
second pair of eyes on this. I encountered some weirdness, with at least 
one major upgrade, earlier in December.

I guess, people will refrain from testing until after the release of pkg 
2.0.

HTH