CRAN: Warning seen on 11/23

While running check against R-devel-gcc15 using [rhub workflows:](https://github.com/detule/odbc/actions/runs/19612970215/job/56161504039)

```
 * checking compiled code ... WARNING
File ‘odbc/libs/odbc.so’:
  Found non-API call to R: ‘DATAPTR’
This entry point may be removed soon.
```