blivet_package_list missing for Oracle Enterprise Linux

[ThiloSolbrig]

blivet_package_list won't be defined on Oracle Enterprise Linux (OEL) as there are no appropriate variable files in vars/directory. Since OEL, from this role's perspective, isn't more than a relabeled RHEL, it's sufficient to symlink every vars/RedHat_?.yml to the appropriate vars/OracleLinux_?.yml to add OEL support.

[plimptm]

Or the other way it could be handled is with a fallback vars/RedHat.yml file similar to the podman role.

[richm]

We have no way to confirm that OEL version N is identical to RHEL version N for every supported version N. I have seen subtle differences in other roles.

However, if someone wants to submit a PR that adds OEL_N.yml symlinks to the corresponding RedHat_N.yml files for every supported version N, I will merge it.