### 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_
KeyPath end_path;
        for (; k < (int)m_path.size(); ++k) {
            end_path.push_back(m_path.at(k));
        }
        
        CKeyID id = m_root_extkey.pubkey.GetID();
        std::copy(id.begin(), id.begin() + 4, origin.fingerprint);
        CExtPubKey xpub;
        CExtKey lh_xprv;
        
        if (cache != nullptr) {
            cache->GetCachedLastHardenedExtPubKey(m_expr_index, xpub);
        }
        if (!xpub.pubkey.IsValid()) {
            
            CExtKey xprv;
            if (!GetDerivedExtKey(arg, xprv, lh_xprv)) return false;
            xpub = lh_xprv.Neuter();
        }
        assert(xpub.pubkey.IsValid());
        
        std::string origin_str = HexStr(origin.fingerprint) + FormatHDKeypath(origin.path);
        out = "[" + origin_str + "]" + EncodeExtPubKey(xpub) + FormatHDKeypath(end_path);
        if (IsRange()) {
            out += "/*";
            assert(m_derive == DeriveType::UNHARDENED);
        }
        return true;
    }
    bool GetPrivKey(int pos, const SigningProvider& arg, CKey& key) const override