fix: The 'warn' method is deprecated
```
examples/language-modeling/run_clm.py:340: DeprecationWarning: The 'warn' method is deprecated, use 'warning' instead
  logger.warn(
```
This PR is fixing many dozes of those with:
```
find . -type d -name ".git" -prune -o -type f -exec perl -pi -e 's|logger.warn\(|logger.warning(|g' {} \;
```

@LysandreJik 