[Closed - code changes not shown on GH for unknown reason] replace `Python-base tokenizer` by `non-fast tokenizer` in error message
# What does this PR do?

As one user rightly pointed out in an issue #17809, when a user receives the V error it is not obvious that a python-based tokenizer refers to a tokenizer class without the term Fast at the end. 

I therefore propose to change the error messages using this term to refer to the term fast which is more easily understood by users.

Fixes #17809


## Before submitting
- [x] This PR fixes a typo or improves the docs (you can dismiss the other checks if that's the case).
- [ ] 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.
- [ ] Did you make sure to update the documentation with your changes? Here are the
      [documentation guidelines](https://github.com/huggingface/transformers/tree/main/docs), and
      [here are tips on formatting docstrings](https://github.com/huggingface/transformers/tree/main/docs#writing-source-documentation).
- [ ] Did you write any new necessary tests?


## Who can review?

Anyone in the community is free to review the PR once the tests have passed.

The docs for this PR live [here](https://moon-ci-docs.huggingface.co/docs/transformers/pr_17825). All of your documentation changes will be reflected on that endpoint.