LibWeb: Remove unuses variable in PaintableBox.cpp

Author: https://github.com/yyny
Commit: e5d89c72a6
Pull-request: https://github.com/LadybirdBrowser/ladybird/pull/4310
Reviewed-by: https://github.com/ADKaster ✅
Reviewed-by: https://github.com/DanShaders
Reviewed-by: https://github.com/Hendiadyoin1
Reviewed-by: https://github.com/alimpfard ✅

Libraries/LibWeb/Painting/PaintableBox.cpp

@@ -851,7 +851,6 @@ void PaintableWithLines::paint(PaintContext& context, PaintPhase phase) const
         return;
 
     bool should_clip_overflow = computed_values().overflow_x() != CSS::Overflow::Visible && computed_values().overflow_y() != CSS::Overflow::Visible;
-    Optional<u32> corner_clip_id;
 
     auto clip_box = absolute_padding_box_rect();
     if (get_clip_rect().has_value()) {