Increase lifetime of non-prod db backups

Now that integration backups occur weekly, we need to extend the lifecycle run to not delete them before new backups are available. This is useful for local development.

terraform/deployments/govuk-publishing-infrastructure/db_backup_s3.tf

@@ -103,7 +103,7 @@ resource "aws_s3_bucket_lifecycle_configuration" "backup_main" {
     id     = "non-production"
     status = var.govuk_environment != "production" ? "Enabled" : "Disabled"
     filter {}
-    expiration { days = 2 }
+    expiration { days = 8 }
     noncurrent_version_expiration { noncurrent_days = 1 }
   }
 }