Include Vector4Dfwd.h for forward declaration

Added forward declaration header for Vector4D.

Author: hkoley

PWGLF/TableProducer/Resonances/hResonanceCorrelationFilter.cxx

@@ -44,7 +44,8 @@
 #include <Framework/OutputObjHeader.h>
 #include <Framework/runDataProcessing.h>
 
-#include <Math/Vector4D.h>
+#include <Math/Vector4D.h> // IWYU pragma: keep (do not replace with Math/Vector4Dfwd.h)
+#include <Math/Vector4Dfwd.h>
 #include <TH1.h>
 
 #include <cmath>