### 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_desc_man);
    if (!m_map_crypted_keys.empty()) {
        return false;
    }
    for (const KeyMap::value_type& key_in : m_map_keys)
    {
        const CKey &key = key_in.second;
        CPubKey pubkey = key.GetPubKey();
        CKeyingMaterial secret(key.begin(), key.end());
        std::vector<unsigned char> crypted_secret;
        if (!EncryptSecret(master_key, secret, pubkey.GetHash(), crypted_secret)) {
            return false;
        }
        m_map_crypted_keys[pubkey.GetID()] = make_pair(pubkey, crypted_secret);
        batch->WriteCryptedDescriptorKey(GetID(), pubkey, crypted_secret);
    }
    m_map_keys.clear();
    return true;
}
util::Result<CTxDestination> DescriptorScriptPubKeyMan::GetReservedDestination(const OutputType type, bool internal, int64_t& index, CKeyPool& keypool)
{
    LOCK(cs_desc_man);
    auto op_dest = GetNewDestination(type);
    index = m_wallet_descriptor.next_index - 1;
    return op_dest;
}
void DescriptorScriptPubKeyMan::ReturnDestination(int64_t index, bool internal, const CTxDestination& addr)