CCM-15020: Fix SNS topic IAM policy?

Author: gareth-allan

infrastructure/terraform/components/dl/sns_topic.tf

@@ -1,6 +1,9 @@
 resource "aws_sns_topic" "main" {
   name = "${local.csi}-test"
+}
 
+resource "aws_sns_topic_policy" "eventbridge_publish" {
+  arn    = aws_sns_topic.main.arn
   policy = data.aws_iam_policy_document.sns_topic_policy_document.json
 }