### 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 (txntype == TxoutType::WITNESS_V1_TAPROOT && ctx == ParseScriptContext::TOP) {
        
        XOnlyPubKey pubkey;
        std::copy(data[0].begin(), data[0].end(), pubkey.begin());
        
        TaprootSpendData tap;
        if (provider.GetTaprootSpendData(pubkey, tap)) {
            
            auto tree = InferTaprootTree(tap, pubkey);
            if (tree) {
                
                bool ok = true;
                std::vector<std::unique_ptr<DescriptorImpl>> subscripts; 
                std::vector<int> depths; 
                for (const auto& [depth, script, leaf_ver] : *tree) {
                    std::unique_ptr<DescriptorImpl> subdesc;
                    if (leaf_ver == TAPROOT_LEAF_TAPSCRIPT) {
                        subdesc = InferScript(CScript(script.begin(), script.end()), ParseScriptContext::P2TR, provider);
                    }
                    if (!subdesc) {
                        ok = false;
                        break;
                    } else {
                        subscripts.push_back(std::move(subdesc));
                        depths.push_back(depth);
                    }
                }
                if (ok) {