Hi! Is there a reason for `default-features` flag to be true [here](https://github.com/pola-rs/pyo3-polars/blob/84c49d327ffaee76827eed035a97a3d412796d64/pyo3-polars/Cargo.toml#L15)? This line majorly slows down compilation, and made me downgrade to 0.19 version.
