cloud: tag resources with keep-until (#21221) (#21225)

This tag will help us destroy things automatically,  let's keep the expiration_date also for backward compatibility

(cherry picked from commit c15234e)

Co-authored-by: Victor Martinez <victormartinezrubio@gmail.com>

Author: mergify[bot]

testing/infra/terraform/modules/tags/output.tf

@@ -7,6 +7,7 @@ locals {
     "build" : var.build
     "ephemeral" : "true"
     "expiration_date" : formatdate("YYYY-MM-DD", timeadd(timestamp(), "24h"))
+    "keep-until" : formatdate("YYYY-MM-DD", timeadd(timestamp(), "24h"))
   }
 }