Manifests: disable default ZRAM config

[jbtrystram]

In #2937 we moved zram-generator to the system-configuration.yaml manifest so it's shared with RHCOS.
However in the centOS stream 9 zram-generator-0.3.2 [1] ships a default config file, resulting in a swap device being created by default.
This ends up breaking kubelet, until kubernetes 1.30 is released

[1] https://gitlab.com/redhat/centos-stream/rpms/rust-zram-generator/-/blob/c9s/zram-generator.conf?ref_type=heads

[travier]

This should probably go into openshift/os, or maybe we should update the package in RHEL as well

[dustymabe]

In centos stream 10 I think the default config is in a subpackage like in Fedora (which makes sense): https://gitlab.com/redhat/centos-stream/rpms/rust-zram-generator/-/blob/c10s/rust-zram-generator.spec?ref_type=heads#L69

I think we should move this removal into a manifest in openshift/os and make it conditional on el9 (c9s or rhel9).

[travier]

You can use the remove-from-package directive from rpm-ostree: https://coreos.github.io/rpm-ostree/treefile/

[jbtrystram]

Thanks @jlebon @dustymabe
I was not sure if the postprocess step needs to be in the same file as the package, i don't know if there is some ordering or not. Based on your answers I guess no. I'll push a separate manifest in rhcos

[travier]

The manifest is first "resolved" (i.e. all includes imported, duplicated fields merged, etc.) and then processed by rpm-ostree so the "order" generally does not matter.

[jbtrystram]

Moved to openshift/os#1479