text: Title: Add `PYTHONWARNDEFAULTENCODING` to pipeline
  Body: Given this comment https://github.com/pydantic/bump-pydantic/pull/85#issuecomment-1632808494, we want to add `PYTHONWARNDEFAULTENCODING` on the pipeline. Check more about it on https://docs.python.org/3/library/io.html#opt-in-encodingwarning.