[CI] Pipelines are started for closed pull requests

[VannTen]

It looks like gitlab-ci pipelines are started when a pull request is closed:

• https://gitlab.com/kargo-ci/kubernetes-sigs-kubespray/-/commit/f0a24938cf8732bf9a3a656812eb55c8c3d6bbd2
• started by https://github.com/kubernetes-sigs/kubespray/pull/11506#issuecomment-2392928063 AFAICT

[VannTen]

/assign @ant31