Prevent Networkmanager from trying to optain IP address via DHCP

on unused/unmanaged network interfaces. Only act on interfaces.
configured via wwctl otherwise system NetworkManager-wait-online.service.
runs into a time out.

overlays/wwinit/rootfs/etc/NetworkManager/conf.d/ww4-unmanaged.ww

@@ -0,0 +1,14 @@
+{{- $host := .BuildHost }}
+{{- $time := .BuildTime }}
+{{- $source := .BuildSource }}
+{{- $filename := print "warewulf-unmanaged.conf" }}
+{{- file $filename }}
+# This file is autogenerated by warewulf
+# Host:   {{ $host }}
+# Time:   {{ $time }}
+# Source: {{ $source }}
+[main]
+plugins=keyfile
+
+[keyfile]
+unmanaged-devices={{ range $connection_id, $netdev := .NetDevs }}except:interface-name:{{- $netdev.Device -}},{{ end }}