chore: bump version to 0.8.0

Voice messages, offline queue, delivery receipts, group call scaling,
recovery code, push notifications scaffolding, admin panel, search v2,
focus-flicker fix.

apps/desktop/src-tauri/Cargo.lock

@@ -678,7 +678,7 @@ dependencies = [
 
 [[package]]
 name = "chat-app-desktop"
-version = "0.1.0"
+version = "0.8.0"
 dependencies = [
  "serde",
  "serde_json",