Markup linebreak (`\`) is ignored with `--wrap-text`

Before:

```typ
Text \
on the new line
```

After:

```typ
Text \ on the new line
```

I first faced this [here](https://forum.typst.app/t/how-do-i-automatically-change-colspan-of-data-cells-that-are-from-a-single-column/3993/2?u=andrew).