ci: disable cluster QA test due to flakiness
Created by: jhchabran
See https://github.com/sourcegraph/sourcegraph/issues/25977
QA:
~/work/sourcegraph main-dry-run/devx/ci-disable-cluster-test $ sg ci preview | grep k8s
~/work/sourcegraph main-dry-run/devx/ci-disable-cluster-test $ git co main
Switched to branch 'main'
Your branch is up to date with 'origin/main'.
~/work/sourcegraph main $ sg ci preview | grep k8s
:k8s: Sourcegraph Cluster (deploy-sourcegraph) QA
:github: :date: :k8s: Trigger k8s updates if current commit is tip of 'main'
~/work/sourcegraph main $