Use LiveKit's Rust SDK on Linux while continue using Swift SDK on Mac

[mgsloan]

Similar to #20826 but keeps the Swift implementation. There were quite a few changes in the call crate, and so that code now has two variants.

Closes #13714

Release Notes:

• Added preliminary Linux support for voice chat and viewing screenshares.

[WeetHet]

Sorry to interfere, before this is merged, could we get a feature to build macOS with the Rust SDK? I understand that it might be difficult to implement, but it would greatly reduce the difficulty in packaging Zed in nixpkgs, as we only have swift 5.8 now. It would be greatly appreciated

[mikayla-maki]

@WeetHet We just pushed a commit that adds a livekit-cross-platform feature to the workspace. Once we've fixed CI, you should be able to enable the cross platform livekit code in nixpkgs by adjusting a few lines here: https://github.com/zed-industries/zed/pull/21550/files#diff-315ed179e69e42c0a098166a7faa7899838376c2649c84fa8cb66643f3813a45R129-R134

Unfortunately, due to the way platform dependencies work, I don't know if we can make this configurable by the CLI

[WeetHet]

@WeetHet We just pushed a commit that adds a livekit-cross-platform feature to the workspace. Once we've fixed CI, you should be able to enable the cross platform livekit code in nixpkgs by adjusting a few lines here: https://github.com/zed-industries/zed/pull/21550/files#diff-315ed179e69e42c0a098166a7faa7899838376c2649c84fa8cb66643f3813a45R129-R134

Unfortunately, due to the way platform dependencies work, I don't know if we can make this configurable by the CLI

Thank you, that's probably more than enough