n-api: remove extra reference from test

Backport-PR-URL: #19447
PR-URL: #18542
Reviewed-By: Michael Dawson <michael_dawson@ca.ibm.com>
Reviewed-By: Tiancheng "Timothy" Gu <timothygu99@gmail.com>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>

test/addons-napi/test_constructor/test_constructor.c

@@ -3,7 +3,6 @@
 
 static double value_ = 1;
 static double static_value_ = 10;
-napi_ref constructor_;
 
 napi_value GetValue(napi_env env, napi_callback_info info) {
   size_t argc = 0;
@@ -80,8 +79,6 @@ napi_value Init(napi_env env, napi_value exports) {
   NAPI_CALL(env, napi_define_class(env, "MyObject", NAPI_AUTO_LENGTH, New,
       NULL, sizeof(properties)/sizeof(*properties), properties, &cons));
 
-  NAPI_CALL(env, napi_create_reference(env, cons, 1, &constructor_));
-
   return cons;
 }