Fix validation of duplicated environment scope

app/models/clusters/cluster.rb

@@ -27,7 +27,7 @@ module Clusters
     accepts_nested_attributes_for :platform_kubernetes, update_only: true
 
     validates :name, cluster_name: true
-    validate :unique_environment_scope, if: :has_project?
+    validate :unique_environment_scope
     validate :restrict_modification, on: :update
 
     delegate :status, to: :provider, allow_nil: true
@@ -110,9 +110,5 @@ module Clusters
 
       true
     end
-
-    def has_project?
-      projects.exists?
-    end
   end
 end