WIP: Solve inconsistent DAG pipeline behaviors

What does this MR do?

Related to #213080 (closed) and #31264 (closed)

This MR is created with the inspiration of this comment:

needs here serves to have test starting as soon as all the needs completes

It means that, needs should not care about whether dependent jobs are failed or succeeded. The goal of needs is whether dependent jobs are completed or not. when keyword of the job should decide if dependent jobs need to be success or failure.

To this end, I've changed the expected behaviors of yaml test cases, and added some new basic tests.

Question ❓

Is this a breaking change ?

Does this MR meet the acceptance criteria?

Conformity

• Changelog entry
• Documentation (if required)
• Code review guidelines
• Merge request performance guidelines
• Style guides
• Database guides
• Separation of EE specific content

Availability and Testing

• Review and add/update tests for this feature/bug. Consider all test levels. See the Test Planning Process.
• Tested in all supported browsers
• Informed Infrastructure department of a default or new setting change, if applicable per definition of done

Security

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• Label as security and @ mention @gitlab-com/gl-security/appsec
• The MR includes necessary changes to maintain consistency between UI, API, email, or other methods
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