The knot.service on Ubuntu Jammy loads an env file which we didn't
install, causing the service to fail:
```
knot.service: Will spawn child (service_enter_start_pre): /usr/sbin/knotc
knot.service: Failed to load environment files: No such file or directory
knot.service: Failed to run 'start-pre' task: No such file or directory
knot.service: Failed with result 'resources'.
knot.service: Service will not restart (restart setting)
```
image_install /lib/tmpfiles.d/knot.conf
image_install "${ROOTLIBDIR:?}/system/knot.service"
image_install -o /etc/dbus-1/system.d/cz.nic.knotd.conf
+ image_install -o /etc/default/knot
# Copy over our configuration
mkdir -p "${workspace:?}/var/lib/knot/zones/" "${workspace:?}/etc/knot/"