[terraform] bump staging identity to 0.38

Summary: pre-requisite for staging identity deployment

Test Plan: terraform plan

Reviewers: ashoat, bartek, will

Reviewed By: ashoat

Subscribers: tomek

Differential Revision: https://phab.comm.dev/D13370

services/terraform/remote/service_identity.tf

@@ -1,5 +1,5 @@
 locals {
-  identity_service_image_tag      = local.is_staging ? "0.37" : "0.37"
+  identity_service_image_tag      = local.is_staging ? "0.38" : "0.37"
   identity_service_server_image   = "commapp/identity-server:${local.identity_service_image_tag}"
   identity_service_container_name = "identity-server"