fix: Velero kubectl image and AWS plugin version

- kubectl: use bitnami/kubectl instead of deprecated bitnamilegacy/kubectl
- AWS plugin: use v1.11.0 (v1.13.1 does not exist)

clusters/lab/backup/velero.yaml

@@ -31,6 +31,9 @@ spec:
         name: vmware-tanzu
       interval: 1h
   values:
+    kubectl:
+      image:
+        repository: docker.io/bitnami/kubectl
     resources:
       requests:
         cpu: 50m
@@ -40,7 +43,7 @@ spec:
         memory: 256Mi
     initContainers:
     - name: velero-plugin-for-aws
-      image: velero/velero-plugin-for-aws:v1.13.1
+      image: velero/velero-plugin-for-aws:v1.11.0
       imagePullPolicy: IfNotPresent
       volumeMounts:
       - mountPath: /target