### 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);
    WatchKeyMap::const_iterator it = mapWatchKeys.find(address);
    if (it != mapWatchKeys.end()) {
        pubkey_out = it->second;
        return true;
    }
    return false;
}
bool LegacyScriptPubKeyMan::GetPubKey(const CKeyID &address, CPubKey& vchPubKeyOut) const
{
    LOCK(cs_KeyStore);
    if (!m_storage.HasEncryptionKeys()) {
        if (!FillableSigningProvider::GetPubKey(address, vchPubKeyOut)) {
            return GetWatchPubKey(address, vchPubKeyOut);
        }
        return true;
    }
    CryptedKeyMap::const_iterator mi = mapCryptedKeys.find(address);
    if (mi != mapCryptedKeys.end())
    {
        vchPubKeyOut = (*mi).second.first;
        return true;
    }
    
    return GetWatchPubKey(address, vchPubKeyOut);
}
CPubKey LegacyScriptPubKeyMan::GenerateNewKey(WalletBatch &batch, CHDChain& hd_chain, bool internal)