### 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_
for (const auto& [hd_seed_id, chain] : hd_chains) {
                if (hd_seed_id != legacy_spkm->GetHDChain().seed_id) {
                    legacy_spkm->AddInactiveHDChain(chain);
                }
            }
        } else {
            pwallet->WalletLogPrintf("Inactive HD Chains found but no Legacy ScriptPubKeyMan\n");
            result = DBErrors::CORRUPT;
        }
    }
    
    LoadResult watch_script_res = LoadRecords(pwallet, batch, DBKeys::WATCHS,
        [] (CWallet* pwallet, DataStream& key, CDataStream& value, std::string& err) {
        CScript script;
        key >> script;
        uint8_t fYes;
        value >> fYes;
        if (fYes == '1') {
            pwallet->GetOrCreateLegacyScriptPubKeyMan()->LoadWatchOnly(script);
        }
        return DBErrors::LOAD_OK;
    });
    result = std::max(result, watch_script_res.m_result);
    
    LoadResult watch_meta_res = LoadRecords(pwallet, batch, DBKeys::WATCHMETA,
        [] (CWallet* pwallet, DataStream& key, CDataStream& value, std::string& err) {
        CScript script;
        key >> script;
        CKeyMetadata keyMeta;
        value >> keyMeta;