Have the RHEL VMs in our integration tests use podman instead of docker

[Molter73]

Description

This is also a workaround for an issue we've been having with RHEL 8 VMs when installing docker, moving over to podman seems to fix the issue.

Checklist

• Investigated and inspected CI test results
• Updated documentation accordingly

Automated testing

• Added unit tests
• Added integration tests
• Added regression tests

If any of these don't apply, please comment below.

Testing Performed

VM creation and provisioning was tested manually, still running integration tests on all RHEL systems by adding the run-multiarch-builds label.

[Molter73]

Due to an issue when mixing images built with docker and podman in a manifest, we'll need to keep using docker on Z and Power VMs. In the future we might want to have a stronger separation between builder and tester VMs so we can provision them with different packages.

[Stringy]

LGTM! Thanks for taking a look at this. Should make things a lot easier for podman on other platforms if we need it