[Testing] Modify autoload on AbstractLazyTestCase to only use vendor/scoper-autoload.php when it exists

[samsonasik]

Fixes rectorphp/rector#9242

[samsonasik]

Manually testing vendor in laminas-servicemanager-migration, this change cause invalid result:

Time: 00:00.629, Memory: 62.00 MB

There were 3 failures:

1) LaminasTest\ServiceManager\Migration\Rector\Class_\ImplementsFactoryInterfaceToPsrFactoryRector\AutoImportRenameUseTest::test with data set #1 ('/Users/samsonasik/www/laminas...hp.inc')
Failed on fixture file "implements_root_factory_interface.php.inc"
Failed asserting that string matches format description.
--- Expected
+++ Actual
@@ @@
 
 namespace LaminasTest\ServiceManager\Migration\Rector\Class_\FixtureAutoImportRenameUse\Fixture;
 
-use Psr\Container\ContainerInterface;
+use Interop\Container\ContainerInterface;
 use Laminas\ServiceManager\Factory\FactoryInterface;
 
 class ServiceFactory
 {
-    public function __invoke(ContainerInterface $container)
+    public function __invoke(\Psr\Container\ContainerInterface $container)

[samsonasik]

@ostrolucky I got it, you need to add:

        "files": [
            "vendor/rector/rector/preload.php"
        ]

under autoload-dev, I created PR to your repository:

• chore!: handle conflict phpunit 12+ conflict preload with rector ostrolucky/rector-rules#44