A user reported to me that they are unable to create a PSBT with a legacy watchonly wallet when they use the GUI. They get an error "The amount exceeds your balance".

I think the issue is that the GUI will retrieve the wallet's balance via `AvailableCoins` before calling `CreateTransaction`. This call to `AvailableCoins` is resulting in fewer coins being returned with recent changes to how `AvailableCoins` works, particularly with additional filtering of spendable coins and preset coins.

***

Note that this does not effect descriptor wallets. A workaround for this issue is to switch to using descriptor wallets. An existing legacy wallet can be turned into a descriptor wallet using the `migratewallet` RPC. However many watchonly legacy wallets are likely the result of importing descriptors via `importmulti`. For such wallets, I recommend creating a new descriptor wallet and re-importing the descriptors.
break;
    case WalletModel::AbsurdFee:
        msgParams.first = tr("A fee higher than %1 is considered an absurdly high fee.").arg(BitcoinUnits::formatWithUnit(model->getOptionsModel()->getDisplayUnit(), model->wallet().getDefaultMaxTxFee()));
        break;
    // 
    case WalletModel::OK:
    default:
        return;
    }
    Q_EMIT message(tr("Send Coins"), msgParams.first, msgParams.second);
}
void SendCoinsDialog::minimizeFeeSection(bool fMinimize)
{
    ui->labelFeeMinimized->setVisible(fMinimize);
    ui->buttonChooseFee  ->setVisible(fMinimize);
    ui->buttonMinimizeFee->setVisible(!fMinimize);
    ui->frameFeeSelection->setVisible(!fMinimize);
    ui->horizontalLayoutSmartFee->setContentsMargins(0, (fMinimize ? 0 : 6), 0, 0);
    fFeeMinimized = fMinimize;
}
void SendCoinsDialog::on_buttonChooseFee_clicked()
{
    minimizeFeeSection(false);
}
void SendCoinsDialog::on_buttonMinimizeFee_clicked()
{
    updateFeeMinimizedLabel();
    minimizeFeeSection(true);
}
void SendCoinsDialog::useAvailableBalance(SendCoinsEntry* entry)