Fix tokenizer auto_map being ignored for custom models (#43219)
* Fix tokenizer auto_map being ignored for custom models (#43202)
PR #42894 added an early-exit to TokenizersBackend when tokenizer_class
doesn't match the registered tokenizer for a model_type. However, this
early-exit was placed before the auto_map check, causing custom tokenizers
with trust_remote_code to be ignored.
This fix moves the auto_map extraction before the early-exit check and adds
tokenizer_auto_map is None to the condition, so models with custom tokenizers
properly use the dynamic module loading path.
* style
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Co-authored-by: Arthur <48595927+ArthurZucker@users.noreply.github.com>
Co-authored-by: vasqu <antonprogamer@gmail.com>