Add EmailDomainBlock.parents scope (#31968)

lib/mastodon/cli/email_domain_blocks.rb

@@ -7,11 +7,11 @@ module Mastodon::CLI
   class EmailDomainBlocks < Base
     desc 'list', 'List blocked e-mail domains'
     def list
-      EmailDomainBlock.where(parent_id: nil).find_each do |entry|
-        say(entry.domain.to_s, :white)
+      EmailDomainBlock.parents.find_each do |parent|
+        say(parent.domain.to_s, :white)
 
         shell.indent do
-          EmailDomainBlock.where(parent_id: entry.id).find_each do |child|
+          EmailDomainBlock.where(parent_id: parent.id).find_each do |child|
             say(child.domain, :cyan)
           end
         end