prometheus/node_exporter: update to 1.8.1

prometheus/map.jinja

@@ -2,6 +2,6 @@
     'default': {
       'release': '2.52.0',
       'alertmanager_release': '0.27.0',
-      'node_exporter_release': '1.8.0',
+      'node_exporter_release': '1.8.1',
     }
 }, grain='os_family', merge=salt['pillar.get']('prometheus')) %}