Remove legacy infra-ansible jobs
The job is now in-tree as Zuul v3 native job, remove it.
Depends-On:
name: openstack-infra/infra-ansible
templates:
- system-required
- check:
- jobs:
- - legacy-infra-ansible
- gate:
- jobs:
- - legacy-infra-ansible
- project:
name: openstack-infra/infra-manual
