lib: remove outdated optimizations

PR-URL: #27380
Reviewed-By: Ruben Bridgewater <ruben@bridgewater.de>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Yongsheng Zhang <zyszys98@gmail.com>
Reviewed-By: Benedikt Meurer <benedikt.meurer@gmail.com>

lib/internal/process/task_queues.js

@@ -93,9 +93,6 @@ function processTicksAndRejections() {
 
 class TickObject {
   constructor(callback, args, triggerAsyncId) {
-    // This must be set to null first to avoid function tracking
-    // on the hidden class, revisit in V8 versions after 6.2
-    this.callback = null;
     this.callback = callback;
     this.args = args;
 

lib/timers.js

@@ -207,9 +207,6 @@ const Immediate = class Immediate {
   constructor(callback, args) {
     this._idleNext = null;
     this._idlePrev = null;
-    // This must be set to null first to avoid function tracking
-    // on the hidden class, revisit in V8 versions after 6.2
-    this._onImmediate = null;
     this._onImmediate = callback;
     this._argv = args;
     this._destroyed = false;