### 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_
SetHDSeed(masterPubKey);
        hd_upgrade = true;
    }
    
    if (!IsFeatureSupported(prev_version, FEATURE_HD_SPLIT) && IsFeatureSupported(new_version, FEATURE_HD_SPLIT)) {
        WalletLogPrintf("Upgrading wallet to use HD chain split\n");
        m_storage.SetMinVersion(FEATURE_PRE_SPLIT_KEYPOOL);
        split_upgrade = FEATURE_HD_SPLIT > prev_version;
        
        if (m_hd_chain.nVersion < CHDChain::VERSION_HD_CHAIN_SPLIT) {
            m_hd_chain.nVersion = CHDChain::VERSION_HD_CHAIN_SPLIT;
            if (!WalletBatch(m_storage.GetDatabase()).WriteHDChain(m_hd_chain)) {
                throw std::runtime_error(std::string(__func__) + ": writing chain failed");
            }
        }
    }
    
    if (split_upgrade) {
        MarkPreSplitKeys();
    }
    
    if (hd_upgrade) {
        if (!NewKeyPool()) {
            error = _("Unable to generate keys");
            return false;
        }
    }
    return true;
}
bool LegacyScriptPubKeyMan::HavePrivateKeys() const