e2e: use tf variable defaults (#19108)

e2e/terraform/terraform.tfvars

@@ -1,12 +1,9 @@
 # Copyright (c) HashiCorp, Inc.
 # SPDX-License-Identifier: BUSL-1.1
 
-region                          = "us-east-1"
-instance_type                   = "t3a.medium"
-server_count                    = "3"
-client_count_ubuntu_jammy_amd64 = "4"
-client_count_windows_2016_amd64 = "0"
-volumes                         = true
+# this default tfvars file expects that you have built nomad
+# with `make dev` or similar (../../ = this repository root)
+# before running `terraform apply`
 
 nomad_local_binary                           = "../../pkg/linux_amd64/nomad"
 nomad_local_binary_client_windows_2016_amd64 = ["../../pkg/windows_amd64/nomad.exe"]

e2e/terraform/variables.tf

@@ -18,7 +18,7 @@ variable "availability_zone" {
 
 variable "instance_type" {
   description = "The AWS instance type to use for both clients and servers."
-  default     = "t2.medium"
+  default     = "t3a.medium"
 }
 
 variable "server_count" {