xp.arange(n) in `__truediv__` is not array-api compatible

# Description

Lines such as the below in [corr](https://github.com/glass-dev/transformcl/blob/main/transformcl.py#L15) are not array-api compatible as `xp.arange(n)` produces an integer dtype which is not allowed in `__truediv__`.

```py
a = (2 * xp.arange(n) + 1) / (4 * xp.pi) * cl
```

## Error message

```
TypeError: Only floating-point dtypes are allowed in __truediv__
```
