Throw error when main db instance method used inside an interactive transaction

```JS
const client = new PGlite();
await client.transaction(async (tx) => {
await tx.query('select 1');
await client.query('select 1'); // process just exits without any errors
})
```

Is this an intended behavior? (I know that I shouldn't do this, but still)

```shell
$ node -v
v20.11.0
$ arch
arm64
```