Update versions inside scylla-manager config (#3790)

## Motivation

Last updates for the ScyllaDB versions

## Proposal

Update the versions

## Test Plan

CI + will deploy a network with this

## Release Plan

- Nothing to do / These changes follow the usual release cycle.

Author: ndr-ds

kubernetes/linera-validator/scylla-manager.values.yaml

@@ -11,9 +11,9 @@ controllerResources:
 scylla:
   developerMode: true
   scyllaImage:
-    tag: 5.4.3
+    tag: 6.2.1
   agentImage:
-    tag: 3.2.8
+    tag: 3.4.1
   datacenter: validator
   racks:
   - name: manager-rack