Add test stack remover script

utils/test-stack-remover.sh

@@ -0,0 +1,16 @@
+#!/usr/bin/env bash
+
+# The CI for this repo can sometimes leave some stacks lying around - every couple of months we need to clean them up.
+# This script will delete any stacks that are in DELETE_FAILED state, that contain the word _test_ in their name, and
+# that are not autoscaling stacks (these are child stacks that will be deleted when their parent is deleted)
+
+set -euo pipefail
+
+aws cloudformation list-stacks \
+  | jq -r ".StackSummaries[] | {StackName, StackStatus} | select(.StackStatus == \"DELETE_FAILED\").StackName" \
+  | grep test \
+  | grep -vi autoscaling \
+  | sort | uniq \
+  | xargs -t -I {} aws cloudformation delete-stack \
+    --stack-name {} \
+    --role-arn "$ROLE_ARN"