Explicitly set utf-8 for Windows in utils required for make fixup
# What does this PR do?

Had a little issue that I could not successfully run `make fixup` due to encoding issues. Windows still does not use UTF-8 by default unfortunately.

When looking through the whole codebase, I found other occurrences where the encoding has not been specified. These are _not_ fixed in this PR. This PR focuses on just the changes needed to at least allow the make commands to work.



## Before submitting
- [x] Did you read the [contributor guideline](https://github.com/huggingface/transformers/blob/main/CONTRIBUTING.md#start-contributing-pull-requests), Pull Request section?


## Who can review?

Tagging @LysandreJik who hinted me to use `make fixup` (here https://github.com/huggingface/transformers/pull/17629#issuecomment-1152359001)


_The documentation is not available anymore as the PR was closed or merged._