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.

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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.
{
        LOCK(m_wallet->cs_wallet);
        return m_wallet->IsLockedCoin(output);
    }
    void listLockedCoins(std::vector<COutPoint>& outputs) override
    {
        LOCK(m_wallet->cs_wallet);
        return m_wallet->ListLockedCoins(outputs);
    }
    util::Result<CTransactionRef> createTransaction(const std::vector<CRecipient>& recipients,
        const CCoinControl& coin_control,
        bool sign,
        int& change_pos,
        CAmount& fee) override
    {
        LOCK(m_wallet->cs_wallet);
        auto res = CreateTransaction(*m_wallet, recipients, change_pos,
                                     coin_control, sign);
        if (!res) return util::Error{util::ErrorString(res)};
        const auto& txr = *res;
        fee = txr.fee;
        change_pos = txr.change_pos;
        return txr.tx;
    }
    void commitTransaction(CTransactionRef tx,