Update tested versions in READMEs
Author: EliahKagan
Pull request: yes

# What does this PR do?

This updates the top-level readme files say the project has been tested with Python 3.8+ (instead of 3.7+) and PyTorch 1.10+ (instead of 1.9+). Versions prior to those are no longer supported as of [v4.31.0](https://github.com/huggingface/transformers/releases/tag/v4.31.0). It also updates some other versions in those lists, that had become out of date earlier. The non-English readme files were less up to date than the English readme file `README.md`.

I allowed my editor to remove trailing whitespace, since it does not appear to have been intentional. Rendered Markdown does not appear changed. After editing all seven READMEs, running `make fix-copies` (required to pass CI) propagated this whitespace removal to (just) one of the `index.md` files, which is why that is also changed. However, I understand if whitespace removal may be viewed as best done separately; if requested, I'd be pleased to modify this PR to retain the trailing whitespace.

## Rationale

My reasoning is similar as the reasoning that was given for the previous update to these versions in #24307. As of [**v4.31.0**](https://github.com/huggingface/transformers/releases/tag/v4.31.0), 🤗 Transformers has dropped support for Python 3.7 (#24091) and for PyTorch 1.9 (#24080). Because of that:

- If the version ranges noted in the readme files are not changed, some users are likely to be mislead into expecting new releases of 🤗 Transformers to support those versions.
- A lesser issue is that the claim that this repository is tested on all those versions will gradually become inaccurate as further contributions are made to the repository, now that those versions are not supported.

## Before submitting

- [x] This PR fixes a typo or improves the docs (you can dismiss the other checks if that's the case).
- [x] Did you read the [contributor guideline](https://github.com/huggingface/transformers/blob/main/CONTRIBUTING.md#start-contributing-pull-requests), Pull Request section?
- [ ] Was this discussed/approved via a Github issue or the [forum](https://discuss.huggingface.co/)? Please add a link to it if that's the case.

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## Who can review?

Anyone in the community is free to review the PR once the tests have passed. Feel free to tag
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 If you know how to use git blame, that is the easiest way, otherwise, here is a rough guide of **who to tag**.
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Models:

- text models: @ArthurZucker and @younesbelkada
- vision models: @amyeroberts
- speech models: @sanchit-gandhi
- graph models: @clefourrier

Library:

- flax: @sanchit-gandhi
- generate: @gante
- pipelines: @Narsil
- tensorflow: @gante and @Rocketknight1
- tokenizers: @ArthurZucker
- trainer: @sgugger

Integrations:

- deepspeed: HF Trainer/Accelerate: @pacman100
- ray/raytune: @richardliaw, @amogkam

Documentation: @sgugger, @stevhliu and @MKhalusova

HF projects:

- accelerate: [different repo](https://github.com/huggingface/accelerate)
- datasets: [different repo](https://github.com/huggingface/datasets)
- diffusers: [different repo](https://github.com/huggingface/diffusers)
- rust tokenizers: [different repo](https://github.com/huggingface/tokenizers)

Maintained examples (not research project or legacy):

- Flax: @sanchit-gandhi
- PyTorch: @sgugger
- TensorFlow: @Rocketknight1

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Comments:
@sgugger Thanks for reviewing! I've made it non-draft so it can be merged, as requested.

Before I saw your comment, I noticed that the listed TensorFlow versions were also older than the minimum `transformers` currently supports and added a commit to deal with that. I'm not sure if that newest commit was part of what you had looked at. If you'd like me to remove that commit, or otherwise make a change related to it, please let me know!

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

The docs for this PR live [here](https://moon-ci-docs.huggingface.co/docs/transformers/pr_24895). All of your documentation changes will be reflected on that endpoint.