Restore missing fabricators (#23951)

spec/fabricators/account_warning_preset_fabricator.rb

+# frozen_string_literal: true
+
+Fabricator(:account_warning_preset) do
+  text { Faker::Lorem.paragraph }
+end

spec/fabricators/list_account_fabricator.rb

+# frozen_string_literal: true
+
+Fabricator(:list_account) do
+  list
+  account
+  before_create { |list_account, _| list_account.list.account.follow!(account) }
+end

spec/fabricators/one_time_key_fabricator.rb

+# frozen_string_literal: true
+
+Fabricator(:one_time_key) do
+  device
+  key_id { Faker::Alphanumeric.alphanumeric(number: 10) }
+  key { Base64.strict_encode64(Ed25519::SigningKey.generate.verify_key.to_bytes) }
+
+  signature do |attrs|
+    signing_key = Ed25519::SigningKey.generate
+    attrs[:device].update(fingerprint_key: Base64.strict_encode64(signing_key.verify_key.to_bytes))
+    Base64.strict_encode64(signing_key.sign(attrs[:key]))
+  end
+end