Find a robust way to determine if we are in a molecule or CI/CD check or not

[widhalmt]

For now we have some special tasks that are used when running in containers in general or Docker specifically. Usually they target CI/CD checks in Molecule.

So we need to make sure we don't influence regular systems running containerized (even when they shouldn't see Ansible tasks after all). Either we use some of the flags Molecule already offers or we introduce a new variable, that's only set during tests. And these tasks only run when this variable is set.