Improve search of Python3 in DNF role in Aix playbook

ref https://github.com/adoptium/infrastructure/issues/3274#issuecomment-1877442593

In the dnf role in the AIX playbook, ansible should look for python3 in more than just /opt/freeware/bin

https://github.com/adoptium/infrastructure/blob/0077e292c4691e2f477f361d6535382dda938363/ansible/playbooks/AdoptOpenJDK_AIX_Playbook/roles/dnf/tasks/main.yml#L9

```
- name: Fail if python3 is not available
stat:
path: /opt/freeware/bin/python3
register: python3_installed
failed_when: not python3_installed.stat.exists
```

Read ansible/playbooks/AdoptOpenJDK_AIX_Playbook/roles/dnf/tasks/main.yml around the Python 3 availability check. Examine how the current stat task only checks /opt/freeware/bin/python3, then define the additional locations Ansible should inspect. Done means the role accepts Python 3 in another supported location and still fails when it is unavailable.

Written by the indexing model from the issue text.