QPageLayout::OutOfBoundsPolicy: add missing trailing comma

Pick-to: 6.8
Task-number: QTBUG-125859
Change-Id: I7834a5bd0884ab23f83813a87e9c51ab34c10797
Reviewed-by: Ahmad Samir <a.samirh78@gmail.com>

src/gui/painting/qpagelayout.h

@@ -42,7 +42,7 @@ public:
 
     enum class OutOfBoundsPolicy {
         Reject,
-        Clamp
+        Clamp,
     };
 
     QPageLayout();