Fix plugin allow list

mixins.yml

@@ -33,7 +33,7 @@ stages:
     # see https://github.com/drupal/core-vendor-hardening
     - composer config --no-plugins --no-interaction allow-plugins.drupal/core-vendor-hardening true
     # Disallowing plugin script.
-    - composer config --no-plugins --no-interaction allow-plugins.php-http/discovery false
+    - composer config --no-plugins --no-interaction allow-plugins.php-http/discovery true
     # Allow PHPStan Extension Installer
     - composer config --no-plugins --no-interaction allow-plugins.phpstan/extension-installer true
     # Allow Composer Installer Extender