Add linux node selector as default (#7481)

charts/ingress-nginx/values.yaml

@@ -555,7 +555,8 @@ controller:
       ##
       priorityClassName: ""
       podAnnotations: {}
-      nodeSelector: {}
+      nodeSelector:
+        kubernetes.io/os: linux
       tolerations: []
       runAsUser: 2000
 
@@ -732,7 +733,8 @@ defaultBackend:
   ## Node labels for default backend pod assignment
   ## Ref: https://kubernetes.io/docs/user-guide/node-selection/
   ##
-  nodeSelector: {}
+  nodeSelector:
+    kubernetes.io/os: linux
 
   ## Annotations to be added to default backend pods
   ##