remove the not-allowed service account specification

Author: Pete-Y-CS

.github/workflows/deploy_private_dev.yml

@@ -48,4 +48,3 @@ jobs:
         with:
           project_id: ${{ vars.PROJECT_ID }}
           deliverables: backend/app_private_dev.yaml
-          service_account: 'gh-builder-service-account@dft-rlg-atip-test.iam.gserviceaccount.com'