lib: remove the use of util.isFunction

PR-URL: #29566
Reviewed-By: Michaël Zasso <targos@protonmail.com>
Reviewed-By: Yongsheng Zhang <zyszys98@gmail.com>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Rich Trott <rtrott@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Trivikram Kamat <trivikr.dev@gmail.com>
Reviewed-By: Luigi Pinca <luigipinca@gmail.com>

lib/inspector.js

@@ -20,7 +20,6 @@ if (!hasInspector)
 
 const EventEmitter = require('events');
 const { validateString } = require('internal/validators');
-const util = require('util');
 const { isMainThread } = require('worker_threads');
 
 const {
@@ -86,7 +85,7 @@ class Session extends EventEmitter {
 
   post(method, params, callback) {
     validateString(method, 'method');
-    if (!callback && util.isFunction(params)) {
+    if (!callback && typeof params === 'function') {
       callback = params;
       params = null;
     }