feat: Bring in Ghost v6.0 support

[HighPriest]

Describe the feature you'd like to request

The API should support v6 of GHOST

Describe the solution you'd like to see

The GHOST_VERSION parameter should accept "v6.0"

Describe alternate solutions

Keeping the var at v5.0, works fine (for now).
I have also looked through the generated code and the version var seems to not be used, at all? So... no issue here, really

Additional information

No response

👨‍👧‍👦 Contributing

• [ ] 🙋‍♂️ Yes, I'd be down to file a PR implementing this feature!