Update ip package to latest Alpine base
There was a wireguard mismatch with the kernel module in the recent kernel
builds.
-FROM linuxkit/alpine:87a0cd10449d72f374f950004467737dbf440630 AS mirror
+FROM linuxkit/alpine:a120ad6aead3fe583eaa20e9b75a05ac1b3487da AS mirror
RUN mkdir -p /out/etc/apk && cp -r /etc/apk/* /out/etc/apk/
RUN apk add --no-cache --initdb -p /out \
alpine-baselayout \
