prometheus-node-exporter: update to 1.4.0

https://github.com/prometheus/node_exporter/releases/tag/v1.4.0

prometheus/map.jinja

@@ -2,6 +2,6 @@
     'default': {
       'release': '2.39.1',
       'alertmanager_release': '0.24.0',
-      'node_exporter_release': '1.3.1',
+      'node_exporter_release': '1.4.0',
     }
 }, grain='os_family', merge=salt['pillar.get']('prometheus')) %}