Refactor to 9-minimal as base image

[sandrobonazzola]

Please describe what you would like to see in this project

Right now plugin must contain a Dockerfile that is based on CentOS Stream 8 (quay.io/centos/centos:stream8).

I would propose to change it and rebase images on Rocky Linux 9-minimal (docker pull rockylinux/rockylinux:9-minimal ; current at https://hub.docker.com/layers/rockylinux/rockylinux/9-minimal/images/sha256-57595b7ba5d7189cc0e749a7dd0324216cbedbca2272187f50f4f3783ad06d7d?context=explore ) which mimics RHEL UBI 9 minimal (https://hub.docker.com/r/redhat/ubi9-minimal) or equivalent from almalinux (https://hub.docker.com/r/almalinux/9-minimal)

Both rocky and alma are available on quay.io as well.

[ghost]

@sandrobonazzola what are the licenses on each of these images? Red Hat UBI doesn't list any license or other information.

[sandrobonazzola]

I couldn't find specific licensing information about the docker images themselves, I hope I got it right:

• For Centos (currently in use) the general licensing page at https://www.centos.org/legal/licensing-policy/ seems to apply, making it a GPLv2 Licensed image.

• For Rocky Linux the general licensing page at https://rockylinux.org/licensing/ seems to apply, making it a 3-Clause BSD Licensed image.

• For Alma Linux https://almalinux.org/p/the-almalinux-os-licensing-policy/ applies, making it GPLv2 as CentOS.