init: Allow '--import <ENV_FILE>' and '--format <FORMAT>' together

### Problem description

I'd like to be able to write this, please.

```sh
pixi init --import environment.yml --format pyproject
```

Or is there an automatic way to convert pixi.toml to pyproject.toml.

Currently this gives the following error:

```
error: the argument '--import <ENV_FILE>' cannot be used with '--format <FORMAT>'
```

pixi: 0.37.0