Create RunRequest payload from CI job
Given a (legacy) CI job, create a RunRequest
payload according to https://docs.gitlab.com/ee/architecture/blueprints/gitlab_steps/runner-integration.html#runrequest-parameters. RunRequest.Steps
should be a JSON-serialized version of https://gitlab.com/gitlab-org/step-runner/-/tree/main/schema/v1. This includes populating RunRequest.Job
.