GPU: Bail out of aquiring Vulkan swapchain if window is hidden

(cherry picked from commit c5edf4bd5b)

src/gpu/vulkan/SDL_gpu_vulkan.c

@@ -9934,6 +9934,11 @@ static bool VULKAN_INTERNAL_AcquireSwapchainTexture(
         SET_STRING_ERROR_AND_RETURN("Cannot acquire a swapchain texture from an unclaimed window!", false);
     }
 
+    if (window->flags & SDL_WINDOW_HIDDEN) {
+        // Edge case, texture is filled in with NULL but not an error
+        return true;
+    }
+
     // If window data marked as needing swapchain recreate, try to recreate
     if (windowData->needsSwapchainRecreate) {
         Uint32 recreateSwapchainResult = VULKAN_INTERNAL_RecreateSwapchain(renderer, windowData);