fix layer and frame duplicate

src/canvas.cpp

@@ -1347,6 +1347,12 @@ int Canvas::anim_duration() const noexcept
     return frames;
 }
 
+void Canvas::anim_update() noexcept
+{
+    for (auto& l : m_layers)
+        l->goto_frame(m_anim_frame);
+}
+
 void Canvas::anim_goto_frame(int frame) noexcept
 {
     m_anim_frame = frame;