Do not store the drupal8 twig variable

src/Handler.php

@@ -73,7 +73,7 @@ class Handler extends BaseHandler {
 
     $drupalCorePackage = $this->getDrupalCorePackage();
     $corePath = $installationManager->getInstallPath($drupalCorePackage);
-    $this->config->setValue('drupal8', version_compare($drupalCorePackage->getVersion(), '9.0.0', '<='));
+    $this->config->setValue('drupal8', version_compare($drupalCorePackage->getVersion(), '9.0.0', '<='), FALSE);
 
     // Directory where the root project is being created.
     $projectRoot = getcwd();