clustermesh: fix remote clusters configuration reset upon deactivation

The blamed commit explicitly reset the list of remote clusters upon
clustermesh deactivation. However, it did so setting the corresponding
setting to nil, which in Cilium v1.16 triggers an error due to not
matching the schema configured. Let's address this by configuring an
empty array instead.

Fixes: b148800 ("clustermesh: reset remote clusters configuration upon disconnection")
Signed-off-by: Marco Iorio <marco.iorio@isovalent.com>

clustermesh/clustermesh.go

@@ -1527,13 +1527,18 @@ func DisableWithHelm(ctx context.Context, k8sClient *k8s.Client, params Paramete
 	helmStrValues := []string{
 		"clustermesh.useAPIServer=false",
 		"clustermesh.config.enabled=false",
-		"clustermesh.config.clusters=null",
 		"externalWorkloads.enabled=false",
 	}
 	vals, err := helm.ParseVals(helmStrValues)
 	if err != nil {
 		return err
 	}
+
+	err = unstructured.SetNestedSlice(vals, []interface{}{}, "clustermesh", "config", "clusters")
+	if err != nil {
+		return err
+	}
+
 	upgradeParams := helm.UpgradeParameters{
 		Namespace:   params.Namespace,
 		Name:        params.HelmReleaseName,