Add VisionOs Supported?

[cr2s367067]

I'm working on a visionOS project and planning to use pkl for configuration.
In ChildProcessMessageTransport will show me the "Cannot find type 'Process' in scope" when I build the project.
Does PKL support visionOS future?

Xcode: 15.3
pkl-swift: 0.2.3
visionOS: 1.1
Project Status: Just Initialization