src: remove unused Converter object

PR-URL: https://github.com/nodejs/node/pull/26243
Reviewed-By: Ben Noordhuis <info@bnoordhuis.nl>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>

src/node_i18n.cc

@@ -204,7 +204,6 @@ class ConverterObject : public BaseObject, Converter {
 
     CHECK_GE(args.Length(), 3);  // Converter, Buffer, Flags
 
-    Converter utf8("utf8");
     ConverterObject* converter;
     ASSIGN_OR_RETURN_UNWRAP(&converter, args[0].As<Object>());
     SPREAD_BUFFER_ARG(args[1], input_obj);