LibWeb: Floating boxes with width:auto don't have definite width

Since layout is required in order to determine the width of such boxes,
they should not be marked as having definite width initially.

Userland/Libraries/LibWeb/Layout/LayoutState.cpp

@@ -197,6 +197,7 @@ void LayoutState::UsedValues::set_node(NodeWithStyleAndBoxModelMetrics& node, Us
         if (size.is_auto()) {
             // NOTE: The width of a non-flex-item block is considered definite if it's auto and the containing block has definite width.
             if (width
+                && !node.is_floating()
                 && node.display().is_block_outside()
                 && node.parent()
                 && !node.parent()->is_floating()