feat(ruby): RSpec's described_class is the constant its example group names, so a spec's calls pin to the class under test (parser version bump) - #338

Node.js 20 is deprecated. The following actions target Node.js 20 but are being forced to run on Node.js 24: actions/checkout@v4. For more information see: https://github.blog/changelog/2025-09-19-deprecation-of-node-20-on-github-actions-runners/