Add variable expansion to cross pipeline artifacts

What does this MR do?

Related to #202093 (closed)

This MR adds the possibility to specify cross pipeline artifacts using environment variables:

build_job:
  stage: build
  script:
    - ls -lhR
  needs:
    - project: $CI_PROJECT_PATH
      job: $SOME_JOB_NAME_IN_OTHER_PROJECT
      ref: $CI_COMMIT_BRANCH
      artifacts: true

Screenshots

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