Update ActiveRecord adapter version check

Fix linting complaint for String constant.

lib/graphiti/adapters/active_record.rb

@@ -304,7 +304,7 @@ def destroy(model_instance)
       end
 
       def close
-        if ::ActiveRecord.version > '7.2'
+        if ::ActiveRecord.version > "7.2"
           ::ActiveRecord::Base.connection_handler.clear_active_connections!
         else
           ::ActiveRecord::Base.clear_active_connections!