LibWeb: Break inclusion cycle by removing unnecessary include

Userland/Libraries/LibWeb/Layout/InitialContainingBlock.h

@@ -8,6 +8,7 @@
 
 #include <LibWeb/DOM/Document.h>
 #include <LibWeb/Layout/BlockContainer.h>
+#include <LibWeb/Layout/LayoutPosition.h>
 
 namespace Web::Layout {
 

Userland/Libraries/LibWeb/Layout/Node.h

@@ -15,7 +15,6 @@
 #include <LibWeb/CSS/StyleProperties.h>
 #include <LibWeb/Forward.h>
 #include <LibWeb/Layout/BoxModelMetrics.h>
-#include <LibWeb/Layout/LayoutPosition.h>
 #include <LibWeb/Painting/PaintContext.h>
 #include <LibWeb/TreeNode.h>