### Is there an existing issue for this?

- [X] I have searched the existing issues

### Current behaviour

crash

### Expected behaviour

no crash

### Steps to reproduce

* Compile 79e8247ddb166f9b980f40249b7372a502402a4d
* Type `migratewallet`

### Relevant log output

```
wallet/scriptpubkeyman.cpp:1915: std::optional<MigrationData> wallet::LegacyScriptPubKeyMan::MigrateToDescriptor(): Assertion `IsMine(desc_spk) != ISMINE_NO' failed.
Aborted (core dumped)
```


### How did you obtain Bitcoin Core

Compiled from source

### What version of Bitcoin Core are you using?

current master

### Operating system and version

Linux

### Machine specifications

_No response_
{
    LOCK(cs_KeyStore);
    WalletBatch batch(m_storage.GetDatabase());
    
    int64_t oldestKey = GetOldestKeyTimeInPool(setExternalKeyPool, batch);
    if (IsHDEnabled() && m_storage.CanSupportFeature(FEATURE_HD_SPLIT)) {
        oldestKey = std::max(GetOldestKeyTimeInPool(setInternalKeyPool, batch), oldestKey);
        if (!set_pre_split_keypool.empty()) {
            oldestKey = std::max(GetOldestKeyTimeInPool(set_pre_split_keypool, batch), oldestKey);
        }
    }
    return oldestKey;
}
size_t LegacyScriptPubKeyMan::KeypoolCountExternalKeys() const
{
    LOCK(cs_KeyStore);
    return setExternalKeyPool.size() + set_pre_split_keypool.size();
}
unsigned int LegacyScriptPubKeyMan::GetKeyPoolSize() const
{
    LOCK(cs_KeyStore);
    return setInternalKeyPool.size() + setExternalKeyPool.size() + set_pre_split_keypool.size();
}
int64_t LegacyScriptPubKeyMan::GetTimeFirstKey() const
{
    LOCK(cs_KeyStore);
    return nTimeFirstKey;
}
std::unique_ptr<SigningProvider> LegacyScriptPubKeyMan::GetSolvingProvider(const CScript& script) const