Backends: SDL_GPU: fixed SDL_GPUViewport initialisation. (#8163, #7998, #7988)

Probably harmless. Amend 8bbccf7

Author: ocornut

backends/imgui_impl_sdlgpu3.cpp

@@ -100,7 +100,7 @@ static void ImGui_ImplSDLGPU3_SetupRenderState(ImDrawData* draw_data, SDL_GPUGra
     viewport.w = (float)fb_width;
     viewport.h = (float)fb_height;
     viewport.min_depth = 0.0f;
-    viewport.min_depth = 1.0f;
+    viewport.max_depth = 1.0f;
     SDL_SetGPUViewport(render_pass,&viewport);
 
     // Setup scale and translation