Remove unneeded header which prevents compilation against recent O3DE

Signed-off-by: Jeremy Ong <[email protected]>

Gem/Code/Source/Automation/ScriptManager.cpp

@@ -31,7 +31,6 @@
 #include <AzFramework/IO/LocalFileIO.h>
 #include <AzFramework/Windowing/WindowBus.h>
 
-#include <AtomCore/Serialization/Json/JsonUtils.h>
 #include <AtomSampleViewerRequestBus.h>
 #include <Utils/Utils.h>