refactor: call infra tests on direct request

Description

This MR ensures that we run infrastructure tests if and only if directly requested.

Supporting information

At the moment, the infra tests are running with any scheduled pipelines. This shouldn't be the case.

Testing instructions

Steps to test the changes:

1. Read the code

Dependencies

N/A

Screenshots

N/A

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

Additional context

N/A