Support [ResourceFlavor|TAS Node] Taints with effect=PreferNoSchedule

[tenzen-y]

What would you like to be added:
It would be great to consider supporting Taints and Tolerations with effect: PreferNoSchedule when flavor assigner and TAS assigns flavor to workloads.

Why is this needed:
Currently, we respect the Node Taints on ResourceFlavor Taints, and Node Taints on TopologyAwareScheduling as well.

But, we respect only NoSchedule and NoExecute effects and do not evaluate PreferNoSchedule in the following:

Basic FlavorAssigning:

kueue/pkg/scheduler/flavorassigner/flavorassigner.go

Lines 492 to 494 in c623953

	taint, untolerated := corev1helpers.FindMatchingUntoleratedTaint(flavor.Spec.NodeTaints, append(podSpec.Tolerations, flavor.Spec.Tolerations...), func(t *corev1.Taint) bool {
	return t.Effect == corev1.TaintEffectNoSchedule || t.Effect == corev1.TaintEffectNoExecute
	})

TAS:

kueue/pkg/cache/tas_flavor_snapshot.go

Lines 499 to 501 in c623953

	taint, untolerated := corev1helpers.FindMatchingUntoleratedTaint(leaf.nodeTaints, tolerations, func(t *corev1.Taint) bool {
	return t.Effect == corev1.TaintEffectNoSchedule || t.Effect == corev1.TaintEffectNoExecute
	})

Completion requirements:
I guess that we can look at what kube-scheduler do for effect:PreferNoSchedule, and then introduce the similar mechanism to Kueue as commonize solution across Flavor (ResourceFlavor Taints) and TAS Node selection.

This enhancement requires the following artifacts:

• Design doc
• API change
• Docs update

The artifacts should be linked in subsequent comments.