Allow canceling all pipelines with auto-cancel

What does this MR do?

Related to #208411 (closed)

interruptible keyword is used to set jobs to be auto-cancelable by new commit for the same branch.

In the current implementation, we only cancel builds for the pipelines that are not "dangling". "dangling" means the source of the pipeline is webide, parent_pipeline or ondemand_dast_scan.

In this MR, we are allowing all pipelines to be canceled by a new commit.

It is behind a feature flag ci_auto_cancel_all_pipelines #275997 (closed)

Screenshots (strongly suggested)

build:
  interruptible: true
  script: sleep 30

deploy:
  trigger:
    include: .child-pipeline.yml

build:
  interruptible: true
  script: sleep 30

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