code: public function onPostAutoloadDump()
      {
          // autoload.p
          $autoload = $this->getAutoload();
  
          if (!empty($autoload)) {
              file_put_contents($this->vendorDir.'/autoload.p', $autoload);
  
              $this->io->writeError('<info>Generating autoload completed</info>');
          }
      }
docs: Handler for ScriptEvents::POST_AUTOLOAD_DUMP