Drop SF5 from tests

Author: andrewmy

Tests/Functional/app/AppKernel.php

@@ -25,14 +25,8 @@ public function getLogDir(): string
         return sys_get_temp_dir().'/EnqueueJobQueue/cache/logs';
     }
 
-    public function registerContainerConfiguration(LoaderInterface $loader)
+    public function registerContainerConfiguration(LoaderInterface $loader): void
     {
-        if (self::VERSION_ID < 60000) {
-            $loader->load(__DIR__.'/config/config-sf5.yml');
-
-            return;
-        }
-
         $loader->load(__DIR__.'/config/config.yml');
     }