WIP: Solve skipped status problem of DAG

What does this MR do?

Related to #213080 (closed)

This MR is aiming to solve the problem that happens when a job needs a skipped job.

The idea is based on creating a dependency tree. Also, another main idea of this MR is to make the processing style of stage and DAG approaches consistently the same.

Notes:

• This MR also reverts the changes of !23405 (merged).
• Legacy processing has not been considered in this MR yet.
• These changes will be behind a feature flag ci_dependency_tree_for_dag.

Screenshots

build_1:
  stage: build
  script: exit 0

build_2:
  stage: build
  script: exit 1

test:
  stage: test
  script: exit 0

deploy:
  stage: deploy
  script: exit 0
  needs: [build_1, test]

Before this MR

After this MR

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

If this MR contains changes to processing or storing of credentials or tokens, authorization and authentication methods and other items described in the security review guidelines:

• 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
• Security reports checked/validated by a reviewer from the AppSec team