chore: update to latest Sentinel Forwarder module (#1250)

Update to the Terraform Sentinel Forwarder module that does
not store its authentication credentials as Lambda env vars.

aws/eks/sentinel.tf

@@ -9,11 +9,11 @@ locals {
 # and https://docs.google.com/document/d/16LLelZ7WEKrnbocrl0Az74JqkCv5DBZ9QILRBUFJQt8/edit#heading=h.z87ipkd84djw
 module "sentinel_forwarder" {
   count             = var.enable_sentinel_forwarding ? 1 : 0
-  source            = "github.com/cds-snc/terraform-modules//sentinel_forwarder?ref=v4.0.3"
+  source            = "github.com/cds-snc/terraform-modules//sentinel_forwarder?ref=v9.3.8"
   function_name     = "sentinel-cloud-watch-forwarder"
   billing_tag_value = "notification-canada-ca-${var.env}"
 
-  layer_arn = "arn:aws:lambda:ca-central-1:283582579564:layer:aws-sentinel-connector-layer:37"
+  layer_arn = "arn:aws:lambda:ca-central-1:283582579564:layer:aws-sentinel-connector-layer:125"
 
   customer_id = var.sentinel_customer_id
   shared_key  = var.sentinel_shared_key