Migrate stopping active encodings to jellyfin-sdk-typescript

[3flex]

This function is currently unused so there were no call sites to fix.

Removing this unused function is an option but there's an open TODO item here:

jellyfin-chromecast/src/components/maincontroller.ts

Lines 507 to 517 in 2990a56

	// TODO Could be useful for garbage collection.
	// It needs to predict if the server side transcode needs
	// to restart.
	// Possibility: Always assume it will. Downside: VTT subs switching doesn't
	// need to restart the transcode.
	//const requiresStoppingTranscoding = false;
	//
	//if (requiresStoppingTranscoding) {
	// window.playerManager.pause();
	// await stopActiveEncodings($scope.playSessionId);
	//}

So I thought it was best to leave it in case that's ever addressed.