In the playbook at  https://opendev.org/openstack/openstack-ansible/src/branch/stable/2023.1/playbooks/openstack-hosts-setup.yml ,  after the play "Basic host setup", it is going to the role 'apt_package_pinning' as shown below:

---
PLAY [Gather host facts] *************************************************************************************************************************************************
META: ran handlers
META: ran handlers
META: ran handlers
Read vars_file 'defaults/{{ install_method }}_install.yml'
Read vars_file 'defaults/{{ install_method }}_install.yml'
Read vars_file 'defaults/{{ install_method }}_install.yml'

PLAY [Basic host setup] **************************************************************************************************************************************************
Read vars_file 'defaults/{{ install_method }}_install.yml'

TASK [Check for a supported Operating System] ****************************************************************************************************************************
task path: /opt/openstack-ansible/playbooks/openstack-hosts-setup.yml:54
container_name: "aio1"
physical_host: "aio1"
ok: [aio1] => {
    "changed": false,
    "msg": "All assertions passed"
}
[aio1] TASK: Check for a supported Operating System (debug)> c
Read vars_file 'defaults/{{ install_method }}_install.yml'
META: ran handlers
Read vars_file 'defaults/{{ install_method }}_install.yml'

TASK [apt_package_pinning : Add apt pin preferences] *********************************************************************************************************************
task path: /etc/ansible/roles/apt_package_pinning/tasks/main.yml:16
container_name: "aio1"
----

Why is it going to the apt pinning role, when it is not mentioned in the playbook anywhere ?
Please explain..

Thanks
elinux