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.
{
    std::vector<unsigned char> pubkey_raw(pubkey.begin(), pubkey.end());
    std::fill(pubkey_raw.begin()+1, pubkey_raw.end(), 0);
    pubkey = CPubKey(pubkey_raw);
    assert(!pubkey.IsFullyValid());
    assert(pubkey.IsValid());
}
BOOST_AUTO_TEST_CASE(WatchOnlyPubKeys)