The release_platform question was added in v1.41.0 but existing projects
with .gitlab-ci.yml in _skip_if_exists won't get the component automatically.

This migration adds the release-platform component to .gitlab-ci.yml for
projects that have release_platform enabled. It reads the component version
from .gitlab-ci.yml.jinja to stay in sync with the template.

AI-assisted: GitLab Duo Agentic Chat (Claude Opus 4.5)

fix: add migration to include release-platform component

See merge request !577