Update: add type hints to check_tokenizers.py (#40094)
* Update check_tokenizers.py
chore(typing): add type hints to check_tokenizers script
- Annotate params/returns for helper functions
- Keep tokenizer instances as `Any` to avoid runtime coupling
- Make `check_LTR_mark` return `bool` explicitly (no behavior change)
* Update check_tokenizers.py
chore(typing): replace Any with PreTrainedTokenizerBase in check_tokenizers.py
- Use transformers.tokenization_utils_base.PreTrainedTokenizerBase for `slow` and `fast` params
- Covers both PreTrainedTokenizer and PreTrainedTokenizerFast
- Exposes required methods (encode, decode, encode_plus, tokenize)
- Removes generic Any typing while staying implementation-agnostic
