LibWeb: Fix bug in placing grid items

Before were resetting the auto_placement_cursor_x to 0 at the end of
the row but this was incorrect, especially since the
auto_placement_cursor_y wasn't being incremented.

This made it so that auto-placed items were occasionally placed before
absolutely-placed ones even after the latter had already been placed.

Userland/Libraries/LibWeb/Layout/GridFormattingContext.cpp

@@ -539,7 +539,6 @@ void GridFormattingContext::run(Box const& box, LayoutMode, AvailableSpace const
                             goto finish;
                         }
                     }
-                    auto_placement_cursor_x = 0;
                 }
                 auto_placement_cursor_x = 0;
                 auto_placement_cursor_y++;