### 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_
{
    LOCK(cs_KeyStore);
    if (!m_storage.HasEncryptionKeys()) {
        return FillableSigningProvider::GetKeys();
    }
    std::set<CKeyID> set_address;
    for (const auto& mi : mapCryptedKeys) {
        set_address.insert(mi.first);
    }
    return set_address;
}
std::unordered_set<CScript, SaltedSipHasher> LegacyScriptPubKeyMan::GetScriptPubKeys() const
{
    LOCK(cs_KeyStore);
    std::unordered_set<CScript, SaltedSipHasher> spks;
    
    for (const auto& key_pair : mapKeys) {
        const CPubKey& pub = key_pair.second.GetPubKey();
        spks.insert(GetScriptForRawPubKey(pub));
        spks.insert(GetScriptForDestination(PKHash(pub)));
    }
    for (const auto& key_pair : mapCryptedKeys) {
        const CPubKey& pub = key_pair.second.first;
        spks.insert(GetScriptForRawPubKey(pub));
        spks.insert(GetScriptForDestination(PKHash(pub)));
    }
    
    
    
    for (const auto& script_pair : mapScripts) {