### 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_
const CScript& script = script_pair.second;
        if (IsMine(script) == ISMINE_SPENDABLE) {
            
            if (!script.IsPayToScriptHash()) {
                spks.insert(GetScriptForDestination(ScriptHash(script)));
            }
            
            int wit_ver = -1;
            std::vector<unsigned char> witprog;
            if (script.IsWitnessProgram(wit_ver, witprog) && wit_ver == 0) {
                spks.insert(script);
            }
        } else {
            
            
            std::vector<std::vector<unsigned char>> sols;
            TxoutType type = Solver(script, sols);
            if (type == TxoutType::MULTISIG) {
                CScript ms_spk = GetScriptForDestination(ScriptHash(script));
                if (IsMine(ms_spk) != ISMINE_NO) {
                    spks.insert(ms_spk);
                }
            }
        }
    }
    
    spks.insert(setWatchOnly.begin(), setWatchOnly.end());
    return spks;
}
std::optional<MigrationData> LegacyScriptPubKeyMan::MigrateToDescriptor()