cleanup(updates.jenkins.io) removes the (unused) `digitalocean.update…

…s.jenkins.io` CNAME record (#707)

Related to jenkins-infra/helpdesk#3954

This PR removes the `digitalocean.updates.jenkins.io` CNAME DNS record
which has been used for [prototyping the new update
center](jenkins-infra/helpdesk#2649). As the
Digital Ocean clusters have been removed and as we don't need this
record, this PR deletes it

updates.jenkins.io.tf

@@ -93,21 +93,6 @@ resource "azurerm_dns_cname_record" "mirrors_updates_jenkins_io" {
   tags                = local.default_tags
 }
 
-# DigitalOcean service CNAME record pointing to the doks-public A record defined in https://github.com/jenkins-infra/azure-net/blob/main/dns-records.tf
-data "azurerm_dns_a_record" "doks_public_public_ipv4_address" {
-  name                = "doks-public-public-ipv4-address"
-  zone_name           = data.azurerm_dns_zone.jenkinsio.name
-  resource_group_name = data.azurerm_resource_group.proddns_jenkinsio.name
-}
-resource "azurerm_dns_cname_record" "digitalocean_updates_jenkins_io" {
-  name                = "digitalocean.updates"
-  zone_name           = data.azurerm_dns_zone.jenkinsio.name
-  resource_group_name = data.azurerm_resource_group.proddns_jenkinsio.name
-  ttl                 = 60
-  record              = data.azurerm_dns_a_record.doks_public_public_ipv4_address.fqdn
-  tags                = local.default_tags
-}
-
 ## NS records for each CloudFlare zone defined in https://github.com/jenkins-infra/cloudflare/blob/main/updates.jenkins.io.tf
 # West Europe
 resource "azurerm_dns_ns_record" "updates_jenkins_io_cloudflare_zone_westeurope" {