d/control: break the circular build-dependency with pve-firewall, and more

d/control: break the circular build-dependency with pve-firewall, and more

Currently pve-network has a (versioned) build-dep of pve-firewall, which has
a (versioned) runtime dependency of a newer version of libpve-network-perl,
which is not available because it has not been built. It turns out that
pve-firewall is only needed in testing, so let's only pull it in if
we don't use the "nocheck" build profile so that we can actually build
pve-network from source.

perl is a build-essential so no need to add it in build-deps.

Fixes: cbc70c81b9a2647a20903b27cabb14c1d6dc6d76
Signed-off-by: Jing Luo <jing@jing.rocks>
Link: https://lore.proxmox.com/mailman.599.1732342430.391.pve-devel@lists.proxmox.com