tools/appsre-build-worker-packer: Run on subscribed 8.5 machine

templates/packer/composer.pkr.hcl

@@ -6,7 +6,7 @@ source "amazon-ebs" "image_builder" {
   region = var.region
 
   # Use a static RHEL 8.5 Cloud Access Image.
-  source_ami          = "ami-06f1e6f8b3457ae7c"
+  source_ami          = "${var.ami_id}"
 
   # Remove previous image before making the new one.
   force_deregister = true

templates/packer/variables.pkr.hcl

@@ -9,6 +9,9 @@ variable "region" {
   default = "us-east-1"
 }
 
+# Base image
+variable "ami_id" { type = string }
+
 # Automatically set by environment variables in GitHub Actions.
 variable "composer_commit" { type = string }
 variable "osbuild_commit" { type = string }