dra API: ensure that pod status contains no duplicate resource claims

This is a follow-up to https://github.com/kubernetes/kubernetes/pull/117351
which just got merged.

pkg/apis/core/validation/validation.go

@@ -4871,6 +4871,7 @@ func validatePodConditions(conditions []core.PodCondition, fldPath *field.Path)
 func validatePodResourceClaimStatuses(statuses []core.PodResourceClaimStatus, podClaims []core.PodResourceClaim, fldPath *field.Path) field.ErrorList {
 	var allErrs field.ErrorList
 
+	claimNames := sets.New[string]()
 	for i, status := range statuses {
 		idxPath := fldPath.Index(i)
 		// There's no need to check the content of the name. If it matches an entry,
@@ -4878,6 +4879,11 @@ func validatePodResourceClaimStatuses(statuses []core.PodResourceClaimStatus, po
 		if !havePodClaim(podClaims, status.Name) {
 			allErrs = append(allErrs, field.Invalid(idxPath.Child("name"), status.Name, "must match the name of an entry in `spec.resourceClaims`"))
 		}
+		if claimNames.Has(status.Name) {
+			allErrs = append(allErrs, field.Duplicate(idxPath.Child("name"), status.Name))
+		} else {
+			claimNames.Insert(status.Name)
+		}
 		if status.ResourceClaimName != nil {
 			for _, detail := range ValidateResourceClaimName(*status.ResourceClaimName, false) {
 				allErrs = append(allErrs, field.Invalid(idxPath.Child("name"), status.ResourceClaimName, detail))