transformers

04c2bae3 - Fix label smoothing incompatibility with multi-label classification (#40296)

Fix label smoothing incompatibility with multi-label classification (#40296) * Fix label smoothing incompatibility with multi-label classification (#40258) * Improve label smoothing multi-label check based on reviewer feedback - Move check from LabelSmoother to Trainer.__init__() for better architecture - Use model.config.problem_type instead of tensor inference for robustness - Warn and disable smoothing instead of raising error for better UX - Update test to verify warning behavior