High input latency with wgpu backend

Describe the bug In the demo application, there is a delay in the application's response to input: windows move with a delay, elements react to the mouse over them with a delay, and button presses also have a delay. This issue is present in 0.28.1 and the master branch.

https://github.com/user-attachments/assets/87578e26-c0a6-4493-bbb9-37e5d863bbab

In my application, I also encountered this delay (Windows, Vulkan backend, egui-wgpu 0.28.1, and egui-winit 0.28.1). I found that the delay depends on the backend: it is lower on DX12 than on Vulkan.

I tested everything on release versions. The web version with egui.rs works fine.

At first, it seemed to me that I was doing something wrong in my application when I encountered this issue, but since it also occurs in the demo application, it seems the problem isn't related to something else; maybe it's with egui-wgpu.