Try to fix workflow

Author: csouchet

.github/workflows/axe-core.yml

@@ -1,12 +1,12 @@
 name: ♿️ A11Y CI with Axe Core
 on:
   workflow_run:
-    workflows: ["Generate Site Preview"]
+    workflows: [Generate Site Preview]
     types:
       - completed
 
 env:
-  WEBSITE_TO_AUDIT: 'https://process-analytics-process-analytics-dev-site_preview-pr-${{ github.event.pull_request.number }}.surge.sh/'
+  WEBSITE_TO_AUDIT: 'https://process-analytics-process-analytics-dev-site_preview-pr-${{ github.event.number }}.surge.sh/'
 
 jobs:
   Axe-CLI: