[fix](job)Fix millisecond offset issue in time window scheduling trigger time calculation

[CalvinKirs]

Abstract:

In the current time window scheduling logic, the calculation of trigger times was not strictly aligned to the second level, which could lead to millisecond offsets. This offset caused issues such as consecutive trigger times at 14:56:59 and 14:57:00, disrupting the correctness of the scheduling.

This PR optimizes the calculation of trigger times to ensure that time points are strictly aligned to the second level, preventing the accumulation of millisecond errors.

Issue Description:

Under a specified window (e.g., 14:50:00 to 14:59:00) and a fixed interval (e.g., every minute), the scheduler generated erroneous trigger times such as:

| 2024-12-04 14:56:59 |
| 2024-12-04 14:57:00 |
| 2024-12-04 14:57:59 |
| 2024-12-04 14:58:00 |

Cause:

The current firstTriggerTime and the loop calculation did not strictly align trigger times to the second level, resulting in erroneous trigger points due to floating-point or millisecond offset accumulation. The end condition for the time window was not aligned to the second level, which could lead to additional trigger times being included.

Fix:

Modification 1: Strictly align the trigger time to the second level.

What problem does this PR solve?

Issue Number: close #xxx

Related PR: #xxx

Problem Summary:

Release note

None

Check List (For Author)

• Test

  • Regression test
  • Unit Test
  • Manual test (add detailed scripts or steps below)
  • No need to test or manual test. Explain why:
    • This is a refactor/code format and no logic has been changed.
    • Previous test can cover this change.
    • No code files have been changed.
    • Other reason

• Behavior changed:

  • No.
  • Yes.

• Does this need documentation?

  • No.
  • Yes.

Check List (For Reviewer who merge this PR)

• Confirm the release note
• Confirm test cases
• Confirm document
• Add branch pick label

[doris-robot]

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1. What problem was fixed (it's best to include specific error reporting information). How it was fixed.
2. Which behaviors were modified. What was the previous behavior, what is it now, why was it modified, and what possible impacts might there be.
3. What features were added. Why was this function added?
4. Which code was refactored and why was this part of the code refactored?
5. Which functions were optimized and what is the difference before and after the optimization?

[CalvinKirs]

run buildall

[github-actions]

PR approved by at least one committer and no changes requested.

[github-actions]

PR approved by anyone and no changes requested.

[morningman]

LGTM