fix imgui backend image count

- should be the number of frames in flight

src/main.zig

@@ -219,8 +219,8 @@ pub fn main() !void {
         .Queue = @ptrFromInt(@intFromEnum(au.Q.handle)),
         .DescriptorPool = @ptrFromInt(@intFromEnum(descriptorPool)),
         .RenderPass = null,
-        .MinImageCount = sc.cinfo.min_image_count,
+        .MinImageCount = 2,
-        .ImageCount = @intCast(sc.images.items.len),
+        .ImageCount = @intCast(flights.flights.len),
         .PipelineRenderingCreateInfo = @bitCast(prci),
         .MSAASamples = 0,
         .PipelineCache = null,