[Tests]04_FF/50_DP&101_NEP tests failed due to wrong md steps

[ZhouXY-PKU]

Describe the Testing Issue

04_FF/50_DP&101_NEP tests failed . md_nsteps=3 in both INPUTs. Previously, MD would run 4 steps, but now only run 3 steps, so the final energies are different. This issue may be related to #6821 .

Additional Context

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Task list for Issue attackers (only for developers)

• Understand the testing issue described by the developer.
• Review the specific test case, expected and actual results, and any error messages.
• Identify the root cause of the test failure or issue.
• If a possible solution is suggested, evaluate its feasibility and effectiveness.
• Implement a fix for the test failure or issue, or create a new test case if needed.
• Verify that the fix resolves the testing issue and the test case passes.
• Review and update any relevant documentation, such as test plans or user guides.
• Ensure the testing issue is resolved and close the ticket.
• Share any lessons learned or best practices with the team to prevent similar issues in the future.