Flaky E2E test for pod groups

[alculquicondor]

What happened:

/kind flake

It seems that sometimes there is a lingering Pod with a finalizer.

Pod groups when Single CQ should allow to schedule a group of diverse pods

{Timed out after 30.001s.
The function passed to Eventually failed at /home/prow/go/src/sigs.k8s.io/kueue/test/e2e/singlecluster/pod_test.go:300 with:
Expected
    <nil>: nil
to be a NotFound error failed [FAILED] Timed out after 30.001s.
The function passed to Eventually failed at /home/prow/go/src/sigs.k8s.io/kueue/test/e2e/singlecluster/pod_test.go:300 with:
Expected
    <nil>: nil
to be a NotFound error
In [It] at: /home/prow/go/src/sigs.k8s.io/kueue/test/e2e/singlecluster/pod_test.go:304 @ 03/25/24 17:25:47.542
}

What you expected to happen:

No flakiness

How to reproduce it (as minimally and precisely as possible):

https://prow.k8s.io/view/gs/kubernetes-jenkins/pr-logs/pull/kubernetes-sigs_kueue/1888/pull-kueue-test-e2e-main-1-29/1772312509823324160

Anything else we need to know?:

Environment:

• Kubernetes version (use kubectl version):
• Kueue version (use git describe --tags --dirty --always):
• Cloud provider or hardware configuration:
• OS (e.g: cat /etc/os-release):
• Kernel (e.g. uname -a):
• Install tools:
• Others: