Remove old obsolete Podman kubic repository

[afbjorklund]

The podman installation is now coming from Debian instead, and the cri-o package also includes conmon and crun now.

https://podman.io/blogs/2021/03/02/podman-support-for-older-distros

[k8s-ci-robot]

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[afbjorklund]

ok-to-build-image

[k8s-ci-robot]

@afbjorklund: The following test failed, say /retest to rerun all failed tests or /retest-required to rerun all mandatory failed tests:

Test name	Commit	Details	Required	Rerun command
pull-minikube-integration	a4bdaee	link	true	/test pull-minikube-integration

Full PR test history. Your PR dashboard. Please help us cut down on flakes by linking to an open issue when you hit one in your PR.

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