As of this writing, Baldur’s Gate 3 updated to ‘Patch 4’ with a lot of changes. Unfortunately, those changes mean there will not be a standalone ‘Patch 4’ to update your game. The developers made a lot of changes to the system files, thus not allowing the ability to create a update patch. You will have to download the whole game again with Patch 4 included.
As of this writing, Fitgirl/DODI have not updated to this version. The only torrent one I know of is a Steam version on 1337x by IGGGAMESCOM; full game w/ Patch 4 included.
Just to note: Patch 4 has broken a lot of mods, and has a few issues of its own. Also, from reports here, it breaks Vulkan on Linux. User beware.
Just an update on this, Patch 5 was released and it was a huge update. Once again, even the developers recommend downloading the whole game again with Patch 5 included. To my knowledge, both Fitgirl/DODI are still offering outdated versions. You can get the latest game + Patch5 on 1337z by IGGGAMESCOM, works well for me.