Include the node groups selector in the API spec ID (#2354)

Author: RobertLucian

Diff for: pkg/types/spec/api.go

@@ -75,6 +75,7 @@ func GetAPISpec(apiConfig *userconfig.API, initialDeploymentTime int64, deployme
 	buf.WriteString(s.Obj(apiConfig.Networking))
 	buf.WriteString(s.Obj(apiConfig.Autoscaling))
 	buf.WriteString(s.Obj(apiConfig.UpdateStrategy))
+	buf.WriteString(s.Obj(apiConfig.NodeGroups))
 	specID := hash.Bytes(buf.Bytes())[:32]
 
 	apiID := fmt.Sprintf("%s-%s-%s", MonotonicallyDecreasingID(), deploymentID, specID) // should be up to 60 characters long