inspector: remove unused promisify

Author: ErickWendel

lib/inspector.js

@@ -22,7 +22,6 @@ const { hasInspector } = internalBinding('config');
 if (!hasInspector)
   throw new ERR_INSPECTOR_NOT_AVAILABLE();
 
-const { promisify } = require('util');
 const EventEmitter = require('events');
 const { queueMicrotask } = require('internal/process/task_queues');
 const {