fix elastic code in transformers>=4.57.6

[meichangsu1]

PR type

• Bug Fix
• New Feature
• Document Updates
• More Models or Datasets Support

PR information

1 修复transformers>=4.57.6 时 _sorted_checkpoints 不存在问题；
2 开启deepspeed 弹性开关时，改为在_init_deepspeed 中通过prepare_deepspeed_elastic_config 方法用deepspeed 中通过compute_elastic_config 计算出来的final_batch_size, micro_batch_size 覆盖实际配置的，因为弹性扩缩容需要保证总体batch_size 不变才不影响训练效果

Experiment results

Paste your experiment result here(if needed).

[gemini-code-assist]

Code Review

This pull request refactors DeepSpeed Elastic configuration setup by moving the initialization logic from a callback to argument initialization, and adds support for fixing optimizer step devices when loading universal checkpoints. The review feedback highlights several robustness improvements, including preventing a device mismatch RuntimeError in _fix_optimizer_step_device by excluding the step tensor when determining the target device, avoiding a potential TypeError if callbacks is uninitialized, guarding against a ZeroDivisionError when calculating gradient accumulation steps, and ensuring checkpoint is a dictionary before setting load_universal to prevent type errors.

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