Rename livekit_client_macos test_app to suppress warnings (#22719)

Current copy/paste conflict between crates triggers warnings during test
runs.
 
<img width="1492" alt="Screenshot 2025-01-06 at 12 41 11"
src="https://github.com/user-attachments/assets/ea7f90ec-bef8-482a-a954-6d5c41b9fd7e"
/>

Release Notes:

- N/A

crates/livekit_client_macos/Cargo.toml

@@ -14,7 +14,7 @@ path = "src/livekit_client.rs"
 doctest = false
 
 [[example]]
-name = "test_app"
+name = "test_app_macos"
 
 [features]
 no-webrtc = []