error: `rustPlatform.fetchCargoTarball` has been removed in 25.05, use `rustPlatform.fetchCargoVendor` instead

### Describe the issue

Running `nixos-unstable` results in:

```
error: `rustPlatform.fetchCargoTarball` has been removed in 25.05, use `rustPlatform.fetchCargoVendor` instead
```

### Additional context

n/a
