ci: delete preview docs of the PR branch

Author: percevalw

.github/workflows/delete-preview-docs.yml

@@ -4,9 +4,6 @@ on:
   workflow_dispatch:
   delete:
 
-env:
-  BRANCH_NAME: ${{ github.head_ref || github.ref_name }}
-
 jobs:
   delete:
     name: Delete Vercel Project
@@ -19,4 +16,4 @@ jobs:
         # Pull Vercel environment
         vercel pull --yes --environment=preview --token=${{ secrets.VERCEL_TOKEN }}
         # Delete vercel project linked to this branch
-        vercel remove edsnlp-$BRANCH_NAME --yes --token=${{ secrets.VERCEL_TOKEN }}
+        vercel remove edsnlp-${{ github.event.ref }} --yes --token=${{ secrets.VERCEL_TOKEN }}