Avoid mutating user-provided arguments in preprocessing utils (#42126)

* fix: deepcopy kwargs to avoid mutating user-provided arguments

* mod: shallow copy instead of deepcopy

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Co-authored-by: Leonardo Emili <lemili@apple.com>

Author: LeonardoEmili

src/transformers/processing_utils.py

@@ -1226,6 +1226,9 @@ class MyProcessingKwargs(ProcessingKwargs, CommonKwargs, TextKwargs, ImagesKwarg
                 Dictionary of per-modality kwargs to be passed to each modality-specific processor.
 
         """
+        # holding a copy to avoid mutating user-provided arguments
+        kwargs = kwargs.copy()
+
         # Initialize dictionaries
         output_kwargs = {
             "text_kwargs": {},