add pretrain dataset

[Jonathans575]

Before submitting

• Lint code. If there are lint issues, please format the code first.

# Install and register `pre-commit` in the project folder pip install pre-commit && pre-commit install # Process previous code files separately pre-commit run --file XXXX.py

• Add test cases into tests folder. If there are codecov issues, please add tests cases first.

PR types

PR changes

Description

[paddle-bot]

Thanks for your contribution!

[codecov-commenter]

Codecov Report

❌ Patch coverage is 12.12121% with 116 lines in your changes missing coverage. Please review.
⚠️ Please upload report for BASE (develop@a83a474). Learn more about missing BASE report.

Files with missing lines	Patch %	Lines
paddleformers/datasets/finetuning.py	13.13%	86 Missing ⚠️
paddleformers/cli/train/sft/workflow.py	0.00%	26 Missing ⚠️
paddleformers/cli/hparams/data_args.py	0.00%	2 Missing ⚠️
paddleformers/cli/train/tuner.py	0.00%	2 Missing ⚠️

❌ Your patch status has failed because the patch coverage (12.12%) is below the target coverage (80.00%). You can increase the patch coverage or adjust the target coverage.

Additional details and impacted files

@@ Coverage Diff @@ ## develop #2803 +/- ## ========================================== Coverage ? 29.22% ========================================== Files ? 335 Lines ? 56399 Branches ? 0 ========================================== Hits ? 16483 Misses ? 39916 Partials ? 0 

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[lugimzzz]

LGTM