inserting large number of rows using unnest with an array column

If I try to insert an array column, I get `error: type "varchar[][]" does not exist`

```
await connection.query(sql`
      INSERT INTO xx (id, txt)
      SELECT *
      FROM ${sql.unnest(
        [
          [1, ['"', "'"]],
          [2, ["'", '"']],
        ],
        [
          'int4',
          'varchar[]'
        ]
      )}
    `)
```