### Is there an existing issue for this?

- [X] I have searched the existing issues

### Current behaviour

I randomly encountered this by loading a wallet created from master with an older version. I could trace it down to bd13dc2f46ea10302a928fcf0f53b7aed77ad260 (#26076), but I don't know descriptor wallets enough to understand what's going on (cc @Sjors @achow101).

### Expected behaviour

`bitcoind` starts, or at least tells me to use a later version if #26076 was a breaking change instead of corrupting `wallet.dat`.

### Steps to reproduce

(master, clean chain): 
`createwallet -regtest ""`
(v25.0rc2):
first `bitcoind -regtest` succeeds
then stop and restart the node: The second `bitcoind -regtest` leads to an InitError:
`Error: Error: Unable to expand wallet descriptor from cache`
now, the wallet cannot be loaded by either version.

### Relevant log output

_No response_

### How did you obtain Bitcoin Core

Compiled from source

### What version of Bitcoin Core are you using?

v25.0rc2 / master

### Operating system and version

Ubuntu

### Machine specifications

_No response_
{
    std::vector<std::vector<unsigned char>> solutions;
    return Solver(dest, solutions) == TxoutType::PUBKEY &&
        (pubKeyOut = CPubKey(solutions[0])).IsFullyValid();
}
bool LegacyScriptPubKeyMan::RemoveWatchOnly(const CScript &dest)
{
    {
        LOCK(cs_KeyStore);
        setWatchOnly.erase(dest);
        CPubKey pubKey;
        if (ExtractPubKey(dest, pubKey)) {
            mapWatchKeys.erase(pubKey.GetID());
        }
        
        
    }
    if (!HaveWatchOnly())
        NotifyWatchonlyChanged(false);
    if (!WalletBatch(m_storage.GetDatabase()).EraseWatchOnly(dest))
        return false;
    return true;
}
bool LegacyScriptPubKeyMan::LoadWatchOnly(const CScript &dest)
{
    return AddWatchOnlyInMem(dest);
}
bool LegacyScriptPubKeyMan::AddWatchOnlyInMem(const CScript &dest)