Hotfix: MacOS Crashes — Worlds Upon The Wind Steam update #818434

This fixes the MacOS version consistently crashing in various, seemingly unrelated situations. The fix is simply switching from Metal to Vulkan as the rendering API. It is still a mystery to me why these crashes suddenly started being reported by numerous users today, even though they are reproducible on all versions of the game since the demo release. In other news, I spent the whole day chasing these issues in vain until I found that the graphics API is the culprit for all of the reported crashes, so the next update may be a bit later than planned.