terraform: drop the DNS import blocks

Both zones and all record sets are in state now; the import blocks
did their job. A plan without them shows no changes.

Assisted-by: Claude:opus-5-5

terraform/dns.tf

@@ -145,17 +145,3 @@ resource "hcloud_zone_rrset" "rr" {
   change_protection = !can(regex(local.unprotected, each.value.name))
   records           = [for value in each.value.records : { value = value }]
 }
-
-# Adopted from the existing zones on 2026-11-12. Harmless once in state;
-# remove after the first apply if you like.
-import {
-  for_each = local.zones
-  to       = hcloud_zone.zone[each.key]
-  id       = each.key
-}
-
-import {
-  for_each = local.rrsets
-  to       = hcloud_zone_rrset.rr[each.key]
-  id       = each.key
-}