[Fix-16202][api] Fix the issue of duplicate predecessor tasks

[xiaoqisu777]

Purpose of the pull request

close #16202

Brief change log

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This pull request is code cleanup without any test coverage.

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This pull request is already covered by existing tests, such as (please describe tests).

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This change added tests and can be verified as follows:

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Pull Request Notice

Pull Request Notice

If your pull request contain incompatible change, you should also add it to docs/docs/en/guide/upgrede/incompatible.md

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Please follow contributing guidelines. @xiaoqisu777

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This pull request has been automatically marked as stale because it has not had recent activity for 120 days. It will be closed in 7 days if no further activity occurs.

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