TypeError: can't subtract offset-naive and offset-aware datetimes

Hi,

I'm working with offset-aware datetime objects and wanted to display them in a friendly way to the user.

## Howto reproduce

```python
from datetime import datetime
import human_readable
date = datetime.fromisoformat("2024-11-02T20:00:00+00:00")  # offset-aware datetime
human_readable.date_time(date)
```
