ServiceSettersToSettersAutodiscoveryRector

Change $services->set(..., ...) to $services->load(..., ...) where meaningful

 use Symfony\Component\DependencyInjection\Loader\Configurator\ContainerConfigurator;

-use App\Services\FistService;
-use App\Services\SecondService;
-
 return static function (ContainerConfigurator $containerConfigurator): void {
     $parameters = $containerConfigurator->parameters();

     $services = $containerConfigurator->services();

-    $services->set(FistService::class);
-    $services->set(SecondService::class);
+    $services->load('App\\Services\\', '../src/Services/*');
 };

Configure your rector.php:

<?php

use Rector\Config\RectorConfig;
use Rector\Symfony\Configs\Rector\Closure\ServiceSettersToSettersAutodiscoveryRector;

return RectorConfig::configure()
    ->withRules([
        ServiceSettersToSettersAutodiscoveryRector::class,
    ]);
SETS:  Configs