fix(core): remove deprecated and defunct wtf* apis (#33949)

These apis have been deprecated in v8, so they should stick around till v10,
but since they are defunct we are removing them early so that they don't take up payload size.

PR Close #33949

packages/core/src/core.externs.js

@@ -8,15 +8,6 @@
  * @externs
  */
 
-// Note: we can't declare an extern for the global variable `ng` as
-// the namespace `ng` is already used within Google
-// for typings for angularJS (via `goog.provide('ng....')`).
-
-/**
- * @suppress {duplicate}
- */
-var wtf;
-
 /**
  * This is needed to declare global `$localize` to let closure compiler know
  * about the global variable.