CI: remove OpenSUSE 15.6 tests

Because pre-installed python version is 3.6, which is deprecated by
Ansible 10.

Signed-off-by: ChengHao Yang <17496418+tico88612@users.noreply.github.com>

.gitlab-ci/kubevirt.yml

@@ -42,7 +42,6 @@ pr:
           - fedora39-kube-router
             # FIXME: this test if broken (perma-failing)
           - openeuler24-calico
-          - opensuse15-6-calico
           - rockylinux9-cilium
           - ubuntu22-calico-all-in-one
           - ubuntu22-calico-all-in-one-upgrade
@@ -125,7 +124,6 @@ pr_extended:
           - debian11-docker
           - debian12-calico
           - debian12-docker
-          - opensuse15-6-docker-cilium
           - rockylinux9-calico
           - ubuntu22-all-in-one-docker
           - ubuntu24-all-in-one-docker

tests/files/opensuse15-6-calico.yml

@@ -1,5 +0,0 @@
----
-# Instance settings
-cloud_image: opensuse-leap-15-6
-
-kube_proxy_mode: nftables

tests/files/opensuse15-6-docker-cilium.yml

@@ -1,12 +0,0 @@
----
-# Instance settings
-cloud_image: opensuse-leap-15-6
-
-# Kubespray settings
-kube_network_plugin: cilium
-
-kube_owner: root
-
-# Docker specific settings:
-container_manager: docker
-etcd_deployment_type: docker