PresentMode isn't configurable (aka Rendy forces vsync)

From what I know, it isn't possible to change the type of PresentMode that Rendy uses without using your own branch and hardcoding the changes.

There are a number of reasons users would want to use something other than FIFO (traditional vsync), some of which might be:

- lower input lag
- benchmarking
- Gsync/Freesync/VRR displays where you're supposed to disable vsync in game and apply it at the driver level

Example of how changing PresentMode currently works: 6bb8c96d691c2c6195ffc93acf77075b315e8874