jsonnet: Include node name in NodeDiskRunningFull

This makes it easier to indetify which node alert is firing for.
Currently only device namespace and pod name were included in
the alert.

jsonnet/kube-prometheus/alerts/node.libsonnet

@@ -7,7 +7,7 @@
           {
             alert: 'NodeDiskRunningFull',
             annotations: {
-              message: 'Device {{ $labels.device }} of node-exporter {{ $labels.namespace }}/{{ $labels.pod }} will be full within the next 24 hours.',
+              message: 'Device {{ $labels.device }} on node {{ $labels.instance }} will be full within the next 24 hours.',
             },
             expr: |||
               (node:node_filesystem_usage: > 0.85) and (predict_linear(node:node_filesystem_avail:[6h], 3600 * 24) < 0)
@@ -20,7 +20,7 @@
           {
             alert: 'NodeDiskRunningFull',
             annotations: {
-              message: 'Device {{ $labels.device }} of node-exporter {{ $labels.namespace }}/{{ $labels.pod }} will be full within the next 2 hours.',
+              message: 'Device {{ $labels.device }} on node {{ $labels.instance }} will be full within the next 2 hours.',
             },
             expr: |||
               (node:node_filesystem_usage: > 0.85) and (predict_linear(node:node_filesystem_avail:[30m], 3600 * 2) < 0)