### 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_
err = "Error reading wallet database: Default Key corrupt";
            return DBErrors::CORRUPT;
        }
        return DBErrors::LOAD_OK;
    });
    result = std::max(result, default_key_res.m_result);
    
    LoadResult wkey_res = LoadRecords(pwallet, batch, DBKeys::OLD_KEY,
        [] (CWallet* pwallet, DataStream& key, CDataStream& value, std::string& err) {
        err = "Found unsupported 'wkey' record, try loading with version 0.18";
        return DBErrors::LOAD_FAIL;
    });
    result = std::max(result, wkey_res.m_result);
    if (result <= DBErrors::NONCRITICAL_ERROR) {
        
        pwallet->WalletLogPrintf("Legacy Wallet Keys: %u plaintext, %u encrypted, %u w/ metadata, %u total.\n",
               key_res.m_records, ckey_res.m_records, keymeta_res.m_records, key_res.m_records + ckey_res.m_records);
        
        if (pwallet->IsLegacy() && (key_res.m_records + ckey_res.m_records + watch_script_res.m_records) != (keymeta_res.m_records + watch_meta_res.m_records)) {
            auto spk_man = pwallet->GetOrCreateLegacyScriptPubKeyMan();
            if (spk_man) {
                LOCK(spk_man->cs_KeyStore);
                spk_man->UpdateTimeFirstKey(1);
            }
        }
    }
    return result;
}
template<typename... Args>
static DataStream PrefixStream(const Args&... args)