Apply uniq to Name.parents

Counterintuitively may not return uniq values, in the test fixtures

app/models/name/taxonomy.rb

@@ -219,7 +219,7 @@ def parents(all: false)
     parents.reject!(&:deprecated) unless parents.all?(&:deprecated)
 
     # Return single parent as an array for backwards compatibility.
-    return parents if all
+    return parents.uniq if all
     return [] unless parents.any?
 
     [parents.first]