util: remove outdated comment

It is probably not necessary to visualize the `code` property as part
of the name of an error since all extra properties will be visible
anyway due to https://github.com/nodejs/node/pull/272431.

PR-URL: https://github.com/nodejs/node/pull/27733
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Michaël Zasso <targos@protonmail.com>

lib/internal/util/inspect.js

@@ -868,7 +868,6 @@ function getFunctionBase(value, constructor, tag) {
 }
 
 function formatError(err, constructor, tag, ctx) {
-  // TODO(BridgeAR): Always show the error code if present.
   let stack = err.stack || ErrorPrototype.toString(err);
 
   // A stack trace may contain arbitrary data. Only manipulate the output