### 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_
return nullptr;
            }
            return std::make_unique<MiniscriptDescriptor>(std::move(parser.m_keys), std::move(node));
        }
    }
    if (ctx == ParseScriptContext::P2SH) {
        error = "A function is needed within P2SH";
        return nullptr;
    } else if (ctx == ParseScriptContext::P2WSH) {
        error = "A function is needed within P2WSH";
        return nullptr;
    }
    error = strprintf("'%s' is not a valid descriptor function", std::string(expr.begin(), expr.end()));
    return nullptr;
}
std::unique_ptr<DescriptorImpl> InferMultiA(const CScript& script, ParseScriptContext ctx, const SigningProvider& provider)
{
    auto match = MatchMultiA(script);
    if (!match) return {};
    std::vector<std::unique_ptr<PubkeyProvider>> keys;
    keys.reserve(match->second.size());
    for (const auto keyspan : match->second) {
        if (keyspan.size() != 32) return {};
        auto key = InferXOnlyPubkey(XOnlyPubKey{keyspan}, ctx, provider);
        if (!key) return {};
        keys.push_back(std::move(key));
    }
    return std::make_unique<MultiADescriptor>(match->first, std::move(keys));
}
std::unique_ptr<DescriptorImpl> InferScript(const CScript& script, ParseScriptContext ctx, const SigningProvider& provider)