Make the lenient project available globally

mixins.yml

@@ -30,7 +30,9 @@ include:
 
 .preparecomposerplugins:
   before_script:
-    - echo "This got removed as it's now part of the default config."
+    # Make the lenient project available globally.
+    - composer global config --no-plugins allow-plugins.mglaman/composer-drupal-lenient true
+    - composer global require mglaman/composer-drupal-lenient
 
 .customreferences:
   LanguageFiles: []