stream: remove unused & undocumented cb

destroy(err, cb) was an undocumented API which
was previously used internally by core modules.
However, this is no longer the case and it should
be possible to safely remove this.

Refs: nodejs#32808

Author: ronag

lib/internal/streams/destroy.js

@@ -1,18 +1,10 @@
 'use strict';
 
-// Undocumented cb() API, needed for core, not for public API.
-// The cb() will be invoked synchronously if _destroy is synchronous.
-// If cb is passed no 'error' event will be emitted.
-function destroy(err, cb) {
+function destroy(err) {
   const r = this._readableState;
   const w = this._writableState;
 
   if ((w && w.destroyed) || (r && r.destroyed)) {
-    if (typeof cb === 'function') {
-      // TODO(ronag): Invoke with `'close'`/`'error'`.
-      cb();
-    }
-
     return this;
   }
 
@@ -52,10 +44,6 @@ function destroy(err, cb) {
       r.closed = true;
     }
 
-    if (typeof cb === 'function') {
-      cb(err);
-    }
-
     if (err) {
       process.nextTick(emitErrorCloseNT, this, err);
     } else {