remove the support of old style input

[codecov[bot]]

Codecov Report

Attention: 1 lines in your changes are missing coverage. Please review.

Comparison is base (ebe7a17) 87.44% compared to head (fdb15b2) 87.57%.

Additional details and impacted files

```diff @@ Coverage Diff @@ ## master #176 +/- ## ========================================== + Coverage 87.44% 87.57% +0.12% ========================================== Files 82 82 Lines 4173 4160 -13 ========================================== - Hits 3649 3643 -6 + Misses 524 517 -7 ``` | [Files](https://app.codecov.io/gh/deepmodeling/dpgen2/pull/176?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=deepmodeling) | Coverage Δ | | |---|---|---| | [dpgen2/entrypoint/args.py](https://app.codecov.io/gh/deepmodeling/dpgen2/pull/176?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=deepmodeling#diff-ZHBnZW4yL2VudHJ5cG9pbnQvYXJncy5weQ==) | `91.47% <ø> (-0.07%)` | :arrow_down: | | [dpgen2/entrypoint/main.py](https://app.codecov.io/gh/deepmodeling/dpgen2/pull/176?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=deepmodeling#diff-ZHBnZW4yL2VudHJ5cG9pbnQvbWFpbi5weQ==) | `54.05% <ø> (-0.82%)` | :arrow_down: | | [dpgen2/entrypoint/submit.py](https://app.codecov.io/gh/deepmodeling/dpgen2/pull/176?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=deepmodeling#diff-ZHBnZW4yL2VudHJ5cG9pbnQvc3VibWl0LnB5) | `70.41% <97.22%> (+1.45%)` | :arrow_up: |

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