[lib/refrepo/valid] nodeset: added in schema-node and ignore homogeneity tests

  Nodes from the same cluster can be in different nodesets

lib/refrepo/valid/homogeneity.rb

@@ -41,6 +41,8 @@ def global_ignore_keys
     ~pdu[6]
     ~pdu[7]
 
+    ~nodeset
+
     ~supported_job_types.max_walltime
 
     ~mic.ip

lib/refrepo/valid/input/schemas/schema-node.yaml

@@ -144,3 +144,4 @@ supported_job_types:
 addressing_plan: optional
 uid: string
 type: string
+nodeset: string