Upgrade linux-lts to 5.15.34 and ZFS to 2.1.4

I know this is usually handled by @ncopa but I wanted to make it easier to do !32655 (closed) at the same time.

I don't upgrade linux-rpi here (yet) since I don't think I can upload a https://dev.alpinelinux.org/archive/rpi-patches/rpi-5.15.34-alpine.patch