fix(os): Remove zfsbootmenu hook from ZFSBootMenu (#6)

While unintuitive this prevents us from having to
move this hook to the end of the HOOKS array.
If user wants SSH in ZBM we first append 'net' to
the HOOKS array then append 'dropbear'. At this
point the explicit 'zfsbootmenu' hook is no longer
last in line in 'HOOKS' array. This causes ZBM to
trip and to not correctly load net and dropbear.

Since the 'zfsbootmenu' hook is added implicitly
by generate-zbm we don't need the explicit hook
at all. Better remove it. This way it doesn't get in
the way.

setup.sh

@@ -704,6 +704,7 @@ EOF
 function configure_zfsbootmenu () {
     #2.9
     paru_install 'zfsbootmenu'
+    in_file_in_array_remove_n '/etc/mkinitcpio.conf' 'HOOKS' 'zfsbootmenu'
 
     if [[ "${part_schema}" = 'gpt' ]]; then
         cat > '/etc/zfsbootmenu/config.yaml' <<EOF