Previously, _node-474c83.k8s.pyrocufflink.black_ was tainted
`du5t1n.me/machine=raspberrypi`, which prevented arbitrary pods from
being scheduled on it. Now that there are two more Raspberry Pi nodes
in the cluster, and arbitrary pods _should_ be scheduled on them, this
taint no longer makes sense. Instead, having specific taints for the
node's roles is more clear.
The *k8s-iot-net-ctrl* group is for the Raspberry Pi that has the Zigbee
and Z-Wave controllers connected to it. This node runs the Zigbee2MQTT
and ZWaveJS2MQTT servers as Kubernetes pods.