chore: sign release workflow commits

[marandaneto]

💡 Motivation and Context

Release workflows commit version bump changes during automated releases. Raw git commit / git push can fail in repositories that require verified commit signatures, so the workflow should use planetscale/ghcommit-action, matching other SDK release workflows.

💚 How did you test it?

• Parsed the updated workflow YAML successfully.

📝 Checklist

• I reviewed the submitted code.
• I added tests to verify the changes.
• I updated the docs if needed.
• No breaking change or entry added to the changelog.

If releasing new changes

• Ran pnpm changeset to generate a changeset file