Use build where possible in fabricators (#25360)

spec/fabricators/device_fabricator.rb

@@ -1,8 +1,8 @@
 # frozen_string_literal: true
 
 Fabricator(:device) do
-  access_token
-  account
+  access_token { Fabricate.build(:access_token) }
+  account { Fabricate.build(:account) }
   device_id        { Faker::Number.number(digits: 5) }
   name             { Faker::App.name }
   fingerprint_key  { Base64.strict_encode64(Ed25519::SigningKey.generate.verify_key.to_bytes) }