[rhcos-4.18] kola: remove IBM CEX device test for the s390x build

[marmijo]

This test was added to coreos-assembler before 4.19 branched, so it ended up in 4.18 but was intended for 4.19+. It recently started failing in 4.18 due to the addition of CEX configuration in RHCOS. Remove the test from 4.18 to unblock the pipeline.

This reverts commit 41e5c4a.

[dustymabe]

LGTM

[jbtrystram]

Ci fail with

[2025-05-14T22:04:55.896Z] kola -p qemu --build latest run-upgrade --rerun --allow-rerun-success=tags=needs-internet --on-warn-failure-exit-77 --arch=x86_64 --output-dir /srv/tmp/kola-GkfFl/kola-upgrade --qemu-image-dir tmp/kola-qemu-cache -v --find-parent-image

[2025-05-14T22:04:55.896Z] 2025-05-14T22:04:55Z cli: Started logging at level INFO

[2025-05-14T22:04:55.896Z] 2025-05-14T22:04:55Z cli: Started logging at level INFO

[2025-05-14T22:04:56.452Z] Error: failed to parse build: json: unknown field "hetzner"

[2025-05-14T22:04:56.452Z] 2025-05-14T22:04:56Z cli: failed to parse build: json: unknown field "hetzner"

[2025-05-14T22:04:56.452Z] failed to execute cmd-kola: exit status 1

we added support for hetzner in #4023 but if that was not into this branch, why would it fail here ?

[travier]

Force merging this one.