UnixPB: Fix package installations for RHEL8+

[steelhead31]

Fixes #4118

Amend DNF/yum installation processes to run via command line rather than via ansible builtin modules.

RHEL8 has a system python of 3.6.8 which dictates how dnf and yum behave.
When running via Ansible with a version of 2.18 or later, the system python and ansible on the controller are incompatible, and this error occurs.

TASK [Common : YUM upgrade all packages] ***************************************
fatal: [169.63.185.12]: FAILED! => {"changed": false, "msg": "Could not import the dnf python module using /usr/bin/python3.9 (3.9.20 (main, Aug 23 2025, 13:51:39) [GCC 8.5.0 20210514 (Red Hat 8.5.0-28)]). Please install `python3-dnf` package or ensure you have specified the correct ansible_python_interpreter. (attempted ['/usr/libexec/platform-python', '/usr/bin/python3', '/usr/bin/python'])", "results": []}

PLAY RECAP *********************************************************************

This may impact RHEL9+ in the future as ansible and python versions progress.

Checklist

• commit message has one of the standard prefixes
• playbook changes run through VPC or QPC (if you have access)

VPC In Progress: https://ci.adoptium.net/job/VagrantPlaybookCheck/2239/

05:58:02.674 VagrantPlaybookCheck » Ubuntu2204,vagrant completed with result SUCCESS
07:52:50.293 VagrantPlaybookCheck » CentOS7,vagrant completed with result SUCCESS
07:52:50.295 VagrantPlaybookCheck » CentOS8,vagrant completed with result SUCCESS
07:52:50.295 VagrantPlaybookCheck » Fedora40,vagrant completed with result SUCCESS

Rerun Failed Due To Node Issue: https://ci.adoptium.net/job/VagrantPlaybookCheck/2240/

[sxa]

I'm intrigued - shouldn't this affect CentOS (Stream) too which should have identical versions of things?

[steelhead31]

I'm intrigued - shouldn't this affect CentOS (Stream) too which should have identical versions of things?

I'd have thought so, but it doesnt... the way the system dnf/yum works is different to RHEL, where RHEL has that odd fixed system python, used by things like dnf/yum, centos doesnt do that.