Reset order transaction cache after proceeding a payment

[Anubarak]

Description
When you save an order and create a transaction afterwards (proceed the payment) you cannot grab the newly created transaction via

$order->getTransactions();

This is because you cache all transaction in $order->getTransactions() but don't invalidate the cache after creating a transaction.
Since Commerce 3.X you included the transactions as search keywords, thus $order->getTransactions() is called after saving the order -> the old transactions are cached.

To Reproduce

1. Save an order via PHP
2. Create a new transaction via Commerce::getInstance()->getPayments()->processPayment() in PHP
3. try to grab the transaction via $order->getTransactions() and see it does not contain the new transaction

Expected behavior

• getting all transactions with the newly created one

[lukeholder]

Thanks, this has been fixed for the next release.