livekit_client: Do not encode video frames on the main thread (#46986)

This can block the mainthread for several milliseconds given large
enough screensizes

Release Notes:

- Fixed screensharing performance on windows and linux
14628482a3Lukas Wirth committed on 1/16/2026, 1:25:55 PM· committed by GitHubparentc2f49c9
4 files changedLine totals unavailable