xrOS Support

[choulepoka]

Is your feature request related to a problem? Please describe.
We're making a xrOS version of our apps, but LaunchDarkly does not work with the Vision Pro SDK

Describe the solution you'd like
Update the Package.swift to swift-tools-version:5.9, and make the LaunchDarkly code to compile on xrOS.

Describe alternatives you've considered
Basically implement a clean-room implementation for evaluating flags, using the REST Api.

Additional context
VisionOS SDK is based on the iOS SDK, so it should be relatively easy to make it work.

[tanderson-ld]

Hello @choulepoka , thank you for your feedback. We have filed this internally as 215854.

[choulepoka]

@tanderson-ld XCode 15.2 with public xrOS support, when can we expect a LD version that officially support xrOS?