Allow requests to localhost for forms-admin

Add localhost:3000 to the allowed hosts for forms-admin so that it
allows requests from forms-runner to the forms-admin API over the
local network without authorization being required.

Author: stephencdaly

.review_apps/ecs_task_definition.tf

@@ -45,6 +45,7 @@ locals {
     { name = "SETTINGS__AUTH_PROVIDER", value = "developer" },
     { name = "SETTINGS__FORMS_ENV", value = "review" },
     { name = "SETTINGS__FORMS_RUNNER__URL", value = "https://${local.runner_review_app_hostname}" },
+    { name = "ALLOWED_HOST_PATTERNS", value = "localhost:3000" }
   ]
 }