Rule source on GitHub

DowngradePreviouslyImplementedInterfaceRector

Downgrade previously implemented interface

 interface ContainerExceptionInterface extends Throwable
 {
 }

-interface ExceptionInterface extends ContainerExceptionInterface, Throwable
+interface ExceptionInterface extends ContainerExceptionInterface
 {
 }

Configure your rector.php:

<?php

use Rector\Config\RectorConfig;
use Rector\DowngradePhp74\Rector\Interface_\DowngradePreviouslyImplementedInterfaceRector;

return RectorConfig::configure()
    ->withRules([
        DowngradePreviouslyImplementedInterfaceRector::class,
    ]);