feat(testing): inject app config in Integration test setup (#1710)

Author: laylatichy

src/Tempest/Framework/Testing/IntegrationTest.php

@@ -122,6 +122,8 @@ protected function setupKernel(): self
         $container = $this->kernel->container;
         $this->container = $container;
 
+        $this->appConfig = $this->container->get(className: AppConfig::class);
+
         return $this;
     }