ImplicitModificationWarning

### Report

```
/ictstr01/home/icb/francesca.drummer/1-Projects/geome/src/geome/transforms/categorize.py:38: ImplicitModificationWarning: Trying to modify attribute `.obs` of view, initializing view as actual.
  getattr(adata, self.axis)[key] = getattr(adata, self.axis)[key].astype("category")
```

### Version information

_No response_