chore(deps): update terraform helm packages

| datasource | package               | from   | to     |
| ---------- | --------------------- | ------ | ------ |
| helm       | grafana               | 8.8.2  | 8.8.4  |
| helm       | kube-prometheus-stack | 68.1.0 | 68.2.1 |

monitoring.tf

@@ -245,7 +245,7 @@ module "prometheus_stack" {
   create = var.create_addons && var.enable_prometheus_stack
 
   chart         = "kube-prometheus-stack"
-  chart_version = "68.1.0"
+  chart_version = "68.2.1"
   repository    = "https://prometheus-community.github.io/helm-charts"
   description   = "Prometheus Stack"
   namespace     = local.monitoring_namespace
@@ -440,7 +440,7 @@ module "grafana" {
   create = var.create_addons && var.enable_grafana
 
   chart         = "grafana"
-  chart_version = "8.8.2"
+  chart_version = "8.8.4"
   repository    = "https://grafana.github.io/helm-charts"
   description   = "Grafana"
   namespace     = local.monitoring_namespace