app/bundles/CoreBundle/Update/Step/RemoveDeletedFilesStep.php

<?php

namespace Mautic\CoreBundle\Update\Step;

use Mautic\CoreBundle\Helper\PathsHelper;
use Psr\Log\LoggerInterface;
use Symfony\Component\Console\Helper\ProgressBar;
use Symfony\Component\Console\Input\InputInterface;
use Symfony\Component\Console\Output\OutputInterface;
use Symfony\Contracts\Translation\TranslatorInterface;

final class RemoveDeletedFilesStep implements StepInterface
{
    private string $appRoot;

    public function __construct(
        private TranslatorInterface $translator,
        PathsHelper $pathsHelper,
        private LoggerInterface $logger
    ) {
        $this->appRoot    = $pathsHelper->getRootPath();
    }

    public function getOrder(): int
    {
        return 20;
    }

    public function shouldExecuteInFinalStage(): bool
    {
        return false;
    }

    public function execute(ProgressBar $progressBar, InputInterface $input, OutputInterface $output): void
    {
        // Make sure we have a deleted_files list otherwise we can't process this step
        if (!file_exists($this->appRoot.'/deleted_files.txt')) {
            return;
        }

        $progressBar->setMessage($this->translator->trans('mautic.core.update.remove.deleted.files'));
        $progressBar->advance();

        $deletedFiles = json_decode(file_get_contents($this->appRoot.'/deleted_files.txt'), true);

        // Before looping over the deleted files, add in our upgrade specific files
        $deletedFiles += ['deleted_files.txt', 'upgrade.php'];

        foreach ($deletedFiles as $file) {
            $this->deleteFile($file);
        }

        @unlink($this->appRoot.'/deleted_files.txt');
    }

    private function deleteFile(string $file): void
    {
        $path = $this->appRoot.'/'.$file;

        if (!file_exists($path)) {
            return;
        }

        // Try setting the permissions to 777 just to make sure we can get rid of the file
        @chmod($path, 0777);

        if (@unlink($path)) {
            return;
        }

        // Failed to delete, reset the permissions to 644 for safety
        @chmod($path, 0644);

        $this->logger->error(
            'UPDATE ERROR: '.$this->translator->trans('mautic.core.update.error.removing.file', ['%path%' => $file])
        );
    }
}