Use enum-generated scope for `IpBlock` in CLI (#28144)

app/models/ip_block.rb

@@ -23,7 +23,7 @@ class IpBlock < ApplicationRecord
     sign_up_requires_approval: 5000,
     sign_up_block: 5500,
     no_access: 9999,
-  }
+  }, prefix: true
 
   validates :ip, :severity, presence: true
   validates :ip, uniqueness: true

app/models/user.rb

@@ -446,7 +446,7 @@ class User < ApplicationRecord
   end
 
   def sign_up_from_ip_requires_approval?
-    sign_up_ip.present? && IpBlock.sign_up_requires_approval.exists?(['ip >>= ?', sign_up_ip.to_s])
+    sign_up_ip.present? && IpBlock.severity_sign_up_requires_approval.exists?(['ip >>= ?', sign_up_ip.to_s])
   end
 
   def sign_up_email_requires_approval?

lib/mastodon/cli/ip_blocks.rb

@@ -105,7 +105,7 @@ module Mastodon::CLI
       tools. Only blocks with no_access severity are returned.
     LONG_DESC
     def export
-      IpBlock.where(severity: :no_access).find_each do |ip_block|
+      IpBlock.severity_no_access.find_each do |ip_block|
         case options[:format]
         when 'nginx'
           say "deny #{ip_block.ip}/#{ip_block.ip.prefix};"