Adds multiple caches per build [RUN ALL RSPEC] [RUN AS-IF-FOSS]

What does this MR do?

Adds the ability to add multiple cache per build or globally.

rspec:
  stage: build
  only:
    - master
  cache:
    - key: KEY
      paths:
        - node_modules/
      policy: pull
    - key: KEY
      paths:
        - node_modules/
      policy: push
  script:
    - echo 'hey'

Note: This is not a breaking change, given as it still accepts a regular hash for a single cache:

rspec:
  stage: build
  only:
    - master
  cache:
    key: KEY
    paths:
      - node_modules/
    policy: pull
  script:
    - echo 'hey'

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

#32814 (closed)