Add a scheduled trigger to run every Monday at 6 AM

Author: NathalieCharbel

.github/workflows/scheduled-e2e-tests.yaml

@@ -2,6 +2,8 @@ name: 'Neo4j-GraphRAG Scheduled E2E Tests'
 
 on:
   workflow_dispatch:
+  schedule:
+    - cron: '0 6 * * 1'
   push:
     branches:
       - main