Remove a voucher from an order

Detaches the given voucher from the order and refunds the redemption back onto the voucher's remaining balance. Use this when a voucher has been mistakenly applied — typically immediately after the customer says "actually, can you take that off?" — or when a refund flow needs to release the voucher value so it can be applied to a different order. The voucher itself is not cancelled; only its association with this order is removed.

The order's totals are recalculated synchronously. If the voucher was the sole source of payment, the order will fall back to an outstanding balance equal to the voucher's previous contribution.