Revert "Allow deletion of duplicated zones" (#1475)

* Revert "Allow deletion of duplicated zones"

This reverts commit 2e71569.

* Fix validation order for immutable fields in zone configuration

Author: hebelsan

pkg/apis/aws/validation/infrastructure.go

@@ -197,50 +197,25 @@ func ValidateInfrastructureConfigUpdate(oldConfig, newConfig *apisaws.Infrastruc
 		newZones = newConfig.Networks.Zones
 	)
 
-	// TODO: @hebelsan remove check after duplicate zones got migrated
-	if !removedDuplicateZones(oldZones, newZones) {
-		if len(oldZones) > len(newZones) {
-			allErrs = append(allErrs, field.Forbidden(field.NewPath("networks.zones"), "removing zones is not allowed"))
-			return allErrs
-		}
-
-		for i, oldZone := range oldZones {
-			idxPath := field.NewPath("networks.zones").Index(i)
-			allErrs = append(allErrs, apivalidation.ValidateImmutableField(oldZone.Name, newConfig.Networks.Zones[i].Name, idxPath.Child("name"))...)
-			allErrs = append(allErrs, apivalidation.ValidateImmutableField(oldZone.Public, newConfig.Networks.Zones[i].Public, idxPath.Child("public"))...)
-			allErrs = append(allErrs, apivalidation.ValidateImmutableField(oldZone.Internal, newConfig.Networks.Zones[i].Internal, idxPath.Child("internal"))...)
-			allErrs = append(allErrs, apivalidation.ValidateImmutableField(oldZone.Workers, newConfig.Networks.Zones[i].Workers, idxPath.Child("workers"))...)
-		}
+	if len(oldZones) > len(newZones) {
+		allErrs = append(allErrs, field.Forbidden(field.NewPath("networks.zones"), "removing zones is not allowed"))
+		return allErrs
 	}
 
+	for i, oldZone := range oldZones {
+		idxPath := field.NewPath("networks.zones").Index(i)
+		allErrs = append(allErrs, apivalidation.ValidateImmutableField(newConfig.Networks.Zones[i].Name, oldZone.Name, idxPath.Child("name"))...)
+		allErrs = append(allErrs, apivalidation.ValidateImmutableField(newConfig.Networks.Zones[i].Public, oldZone.Public, idxPath.Child("public"))...)
+		allErrs = append(allErrs, apivalidation.ValidateImmutableField(newConfig.Networks.Zones[i].Internal, oldZone.Internal, idxPath.Child("internal"))...)
+		allErrs = append(allErrs, apivalidation.ValidateImmutableField(newConfig.Networks.Zones[i].Workers, oldZone.Workers, idxPath.Child("workers"))...)
+	}
 	if oldConfig.DualStack != nil && oldConfig.DualStack.Enabled && (newConfig.DualStack == nil || !newConfig.DualStack.Enabled) {
 		dualStackPath := field.NewPath("dualStack.enabled")
 		allErrs = append(allErrs, field.Forbidden(dualStackPath, "field can't be changed from \"true\" to \"false\""))
 	}
 	return allErrs
 }
 
-// removeDuplicateZones checks if duplicate zones got removed from the old
-// TODO: @hebelsan remove after duplicate zones got migrated
-func removedDuplicateZones(old []apisaws.Zone, new []apisaws.Zone) bool {
-	// old must have more zones than new, otherwise we would not be able to remove duplicates
-	if len(old) <= len(new) {
-		return false
-	}
-
-	oldZoneNames := sets.New[string]()
-	for _, zone := range old {
-		oldZoneNames.Insert(zone.Name)
-	}
-
-	newZoneNames := sets.New[string]()
-	for _, zone := range new {
-		newZoneNames.Insert(zone.Name)
-	}
-
-	return oldZoneNames.Equal(newZoneNames)
-}
-
 var (
 	reservedTagKeys        = []string{"Name"}
 	reservedTagKeyPrefixes = []string{