add vars. prefix to DOCKERDESKTOP_APP_ID

Signed-off-by: Guillaume Lours <[email protected]>

.github/workflows/merge.yml

@@ -131,7 +131,7 @@ jobs:
         id: generate_token
         uses: tibdex/github-app-token@v1
         with:
-          app_id: ${{ DOCKERDESKTOP_APP_ID }}
+          app_id: ${{ vars.DOCKERDESKTOP_APP_ID }}
           private_key: ${{ secrets.DOCKERDESKTOP_APP_PRIVATEKEY }}
       -
         name: Trigger Docker Desktop e2e with edge version