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->GetAddressReceiveRequests();
    }
    bool setAddressReceiveRequest(const CTxDestination& dest, const std::string& id, const std::string& value) override {
        LOCK(m_wallet->cs_wallet);
        WalletBatch batch{m_wallet->GetDatabase()};
        return m_wallet->SetAddressReceiveRequest(batch, dest, id, value);
    }
    bool displayAddress(const CTxDestination& dest) override
    {
        LOCK(m_wallet->cs_wallet);
        return m_wallet->DisplayAddress(dest);
    }
    bool lockCoin(const COutPoint& output, const bool write_to_db) override
    {
        LOCK(m_wallet->cs_wallet);
        std::unique_ptr<WalletBatch> batch = write_to_db ? std::make_unique<WalletBatch>(m_wallet->GetDatabase()) : nullptr;
        return m_wallet->LockCoin(output, batch.get());
    }
    bool unlockCoin(const COutPoint& output) override
    {
        LOCK(m_wallet->cs_wallet);
        std::unique_ptr<WalletBatch> batch = std::make_unique<WalletBatch>(m_wallet->GetDatabase());
        return m_wallet->UnlockCoin(output, batch.get());
    }
    bool isLockedCoin(const COutPoint& output) override