### 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_
if (sigversion == IsMineSigVersion::TOP) {
            break;
        }
        
        
        
        
        
        std::vector<valtype> keys(vSolutions.begin()+1, vSolutions.begin()+vSolutions.size()-1);
        if (!PermitsUncompressed(sigversion)) {
            for (size_t i = 0; i < keys.size(); i++) {
                if (keys[i].size() != 33) {
                    return IsMineResult::INVALID;
                }
            }
        }
        if (HaveKeys(keys, keystore)) {
            ret = std::max(ret, IsMineResult::SPENDABLE);
        }
        break;
    }
    } 
    if (ret == IsMineResult::NO && keystore.HaveWatchOnly(scriptPubKey)) {
        ret = std::max(ret, IsMineResult::WATCH_ONLY);
    }
    return ret;
}
} 
isminetype LegacyScriptPubKeyMan::IsMine(const CScript& script) const