Fix slow reference parser test case

lib/banzai/reference_parser/base_parser.rb

@@ -178,7 +178,10 @@ module Banzai
             collection.where(id: to_query).each { |row| cache[row.id] = row }
           end
 
-          ids.uniq.map { |id| cache[id] }.compact
+          ids.each_with_object([]) do |id, array|
+            row = cache[id]
+            array << row if row
+          end
         else
           collection.where(id: ids)
         end

spec/lib/banzai/reference_parser/base_parser_spec.rb

@@ -323,6 +323,9 @@ RSpec.describe Banzai::ReferenceParser::BaseParser do
       it 'will not overflow the stack' do
         ids = 1.upto(1_000_000).to_a
 
+        # Avoid executing a large, unnecessary SQL query
+        expect(User).to receive(:where).with(id: ids).and_return(User.none)
+
         expect { subject.collection_objects_for_ids(User, ids) }.not_to raise_error
       end
     end