Delete lakedrops default config cache for each step

mixins.yml

@@ -30,7 +30,7 @@ include:
 
 .preparecomposerplugins:
   before_script:
-    - echo "This got removed as it's now part of the default config."
+    - rm -rf /root/.composer/cache/lakedrops-drupal-config/ || true
 
 .customreferences:
   LanguageFiles: []