fts5vocab is not supported

Dialect: sqlite:3.25

failing sql:

```sql
CREATE VIRTUAL TABLE foo_fts_vocab USING fts5vocab(foo_fts, 'row');
```

where foo_fts is a FTS5 virtual table.

This gives the following error in the build log:

```null cannot be cast to non-null type com.squareup.sqldelight.core.lang.psi.ColumnTypeMixin```