qtwebengine: Increase build timeout to 24h

The default 10h timeout caused the cancellation of builds on
aarch64-linux builders.
Perhaps counterintuitively, this wastes resources because it
requires a restart, but never completes.

https://hydra.nixos.org/build/136917190

pkgs/development/libraries/qt-5/modules/qtwebengine.nix

@@ -229,6 +229,8 @@ qtModule {
     description = "A web engine based on the Chromium web browser";
     maintainers = with maintainers; [ matthewbauer ];
     platforms = platforms.unix;
+    # This build takes a long time; particularly on slow architectures
+    timeout = 24 * 3600;
   };
 
 }