Updates FRTIB to latest to reduce indexers per site to 2

prod/aws-us-gov/mdr-prod-frtib/160-splunk-indexer-cluster/terragrunt.hcl

@@ -13,7 +13,7 @@ locals {
 # working directory, into a temporary folder, and execute your Terraform commands in that folder.
 terraform {
   # Double slash is intentional and required to show root of modules
-  source = "git@github.xdr.accenturefederalcyber.com:mdr-engineering/xdr-terraform-modules.git//base/splunk_servers/indexer_cluster?ref=v5.2.3"
+  source = "git@github.xdr.accenturefederalcyber.com:mdr-engineering/xdr-terraform-modules.git//base/splunk_servers/indexer_cluster?ref=v5.2.7"
 }
 
 dependency "vpc" {