Log Message:
finance/ruby-braintree: update to 4.21.0

4.21.0 (2024-07-23)

* Add foreign_retailer to Transaction
* Add international_phone to Address and Customer
* Add funding_source_description to PayPalAccount
* Add missing GooglePayCard error code
* Add REFUND_FAILED to Webhook Notification
* Add final_capture to Transaction _submit_for_partial_settlement_signature
* Deprecate paypal_tracking_id in favor of paypal_tracker_id in
  package_details.rb