Add `grept-cronjob.yml`

[lonegunmanb]

Description

Type of Change

• [ ] Non-module change (e.g. CI/CD, documentation, etc.)
• [ ] Azure Verified Module updates:
  • [ ] Bugfix containing backwards compatible bug fixes
  • [ ] Someone has opened a bug report issue, and I have included "Closes #{bug_report_issue_number}" in the PR description.
  • [ ] The bug was found by the module author, and no one has opened an issue to report it yet.
  • [ ] Feature update backwards compatible feature updates.
  • [ ] Breaking changes.
  • [ ] Update to documentation

Checklist

• [ ] I'm sure there are no other open Pull Requests for the same update/change
• [ ] My corresponding pipelines / checks run clean and green without any errors or warnings
• [ ] I did run all pre-commit checks