build: need the entire release repo for a release init command (#1884)

Towards #1840

Author: chingor13

infra/prod/stage-release.yaml

@@ -22,7 +22,6 @@ steps:
     waitFor: ['-']
     args:
       - 'clone'
-      - '--depth=1'
       - $_FULL_REPOSITORY
   - name: 'us-central1-docker.pkg.dev/cloud-sdk-librarian-prod/images-prod/librarian'
     id: stage-release