private function purgeOldFiles(string $webDir): void
    {
        if (file_exists($webDir.'/app_dev.php')) {
            $this->fs->remove($webDir.'/app_dev.php');
            $this->io->writeln('Deleted the <comment>web/app_dev.php</comment> file.');
        }

        if (file_exists($webDir.'/install.php')) {
            $this->fs->remove($webDir.'/install.php');
            $this->io->writeln('Deleted the <comment>web/install.php</comment> file.');
        }
    }