chore: added rule for infra test

Description

Changes the infrastructure test so that it runs only when scheduled. In this way it can run on a schedule.

Supporting information

https://gitlab.com/opencraft/ops/grove-stage-digitalocean/-/pipelines/657143545

Testing instructions

Check that the above pipeline was triggered via the schedule.

Checklist

If any of the items below is not applicable, do not remove them, but put a check in it.

• All providers include the new feature/change
• All affected providers can provision new clusters
• Unit tests are added/updated
• Documentation is added/updated
• The TOOLS_CONTAINER_IMAGE_VERSION in ci_vars.yml is updated
• The grove-template repository is updated