run keyword script property does not accept array syntax as documented

Summary

The documentation states that within the run keyword, the script property accepts "a string or array of strings." However, using an array results in a validation error.

Steps to reproduce

Use the following .gitlab-ci.yml:

stages:
  - test

test_run_keyword:
  stage: test
  image: alpine:latest
  run:
    - name: say_script
      script:
        - echo "hello"
        - echo "hello2"

What is the current bug behavior?

Pipeline fails with the following error:

This GitLab CI configuration is invalid: jobs:job run object property at `/1/script` is a disallowed additional property

What is the expected correct behavior?

The script property within run should accept an array of strings as documented.

Workaround

Use YAML block scalar syntax instead of an array:

    - name: say_script
      script: |
        echo "hello"
        echo "hello2"

Environment

• GitLab.com (SaaS)
• GitLab version: 18.9.0

Additional context

The run keyword was introduced in GitLab 17.3 and the documentation notes it is "available for testing, but not ready for production use." The Pipeline Editor also shows a schema warning ("Incorrect type. Expected string") when using array syntax, suggesting the JSON schema hasn't been updated to match the documented behavior.