Depend on a proper kernel package

We trigger this by a build profile so we can disable it in
CI where we still want to fetch latest kernels via wget.

We don't make this architecture dependent since that
would mean switching librem5-base to arch any which
in turn would mean having separate germinate lists
for arm64 and amd64.
We might want to do that later on when switching to seeds
to fill the package lists (which we can do now that we
build off of pureos as well).
1 job for kernel-deb in 50 seconds (queued for 1 second)