Change domains.delete_at database column type to date, rename to

`delete_date`

Closes #1125

lib/serializers/registrant_api/domain.rb

@@ -36,7 +36,7 @@ module Serializers
           legacy_registrar_id: domain.legacy_registrar_id,
           legacy_registrant_id: domain.legacy_registrant_id,
           outzone_at: domain.outzone_at,
-          delete_at: domain.delete_at,
+          delete_date: domain.delete_date,
           registrant_verification_asked_at: domain.registrant_verification_asked_at,
           registrant_verification_token: domain.registrant_verification_token,
           pending_json: domain.pending_json,

lib/tasks/data_migrations/convert_domain_delete_date.rake

@@ -0,0 +1,16 @@
+namespace :data_migrations do
+  task convert_domain_delete_date: :environment do
+    processed_domain_count = 0
+
+    Domain.transaction do
+      Domain.find_each do |domain|
+        next unless domain.delete_date
+
+        domain.update_columns(delete_date: domain.delete_date + 1.day)
+        processed_domain_count += 1
+      end
+    end
+
+    puts "Domains processed: #{processed_domain_count}"
+  end
+end

lib/tasks/domains/release.rake

@@ -1,6 +1,6 @@
 namespace :domains do
   desc <<~TEXT.gsub("\n", "\s")
-    Releases domains with past `delete_at` by either sending them to the auction or discarding,
+    Releases domains with past `delete_date` by either sending them to the auction or discarding,
     depending on `release_domains_to_auction` setting
   TEXT