[aijadugar]

Description:

Replaced deepcopy with a shallow copy to avoid AttributeError with fast tokenizers.

Added a test (tests/utils/test_processor_utils.py) to verify multiple tokenizers save/load correctly.

Fix #41837

[ArthurZucker]

Thanks @aijadugar for the fix! ProcessorMixin.to_dict was since reworked in #44894 to exclude tokenizer attributes before deep-copying, which avoids the fast-tokenizer deepcopy issue from #41837. Closing as this is now covered on main; please open a new issue if you still see the error.