Fix arn

Author: francisco-videira-nhs

infrastructure/terraform/components/api/event_source_mapping_status_updates_to_handler.tf

@@ -1,6 +1,6 @@
 resource "aws_lambda_event_source_mapping" "status_updates_sqs_to_status_update_handler" {
   event_source_arn                   = module.letter_status_updates_queue.sqs_queue_arn
-  function_name                      = module.letter_status_update.arn
+  function_name                      = module.letter_status_update.function_arn
   batch_size                         = 10
   maximum_batching_window_in_seconds = 1
   scaling_config { maximum_concurrency = 10 }