LibWeb: Convert InlineLevelIterator/LineBox/LineBuilder to new px units

Author: https://github.com/AtkinsSJ
Commit: 76047d1932
Pull-request: https://github.com/SerenityOS/serenity/pull/16514
Reviewed-by: https://github.com/MacDue
Reviewed-by: https://github.com/linusg ✅

Userland/Libraries/LibWeb/Layout/BlockFormattingContext.cpp

@@ -713,7 +713,7 @@ void BlockFormattingContext::layout_floating_box(Box const& box, BlockContainer
     // First we place the box normally (to get the right y coordinate.)
     // If we have a LineBuilder, we're in the middle of inline layout, otherwise this is block layout.
     if (line_builder) {
-        auto y = line_builder->y_for_float_to_be_inserted_here(box);
+        auto y = line_builder->y_for_float_to_be_inserted_here(box).value();
         box_state.set_content_y(y + box_state.margin_box_top());
     } else {
         place_block_level_element_in_normal_flow_vertically(box, y + box_state.margin_box_top());