GitLab-CI：仅当删除分支时才运行作业

Question

在gitlab Runner中，我要在删除分支后运行作业。

（。yml示例）

creat job:
  stage: delete
  script:
    - echo 'branch delete'
  only:
   - ????

create:
  stage: delete
  script:
    - echo 'branch delete'
  rules:
    - if: '????'