Use LiveKit's Rust SDK on Linux while continue using Swift SDK on Mac (#21550)

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.

---------

Co-authored-by: Kirill Bulatov <mail4score@gmail.com>
Co-authored-by: Kirill Bulatov <kirill@zed.dev>
Co-authored-by: Mikayla <mikayla@zed.dev>

crates/livekit_server/build.rs

@@ -0,0 +1,9 @@
+fn main() {
+    prost_build::Config::new()
+        .type_attribute("SendDataResponse", "#[allow(clippy::empty_docs)]")
+        .compile_protos(
+            &["vendored/protocol/livekit_room.proto"],
+            &["vendored/protocol"],
+        )
+        .unwrap();
+}