Core/Misc: Remove unused headers

src/server/game/AI/SmartScripts/SmartAI.cpp

@@ -21,11 +21,7 @@
 #include "GridDefines.h"
 #include "GridNotifiers.h"
 #include "SpellMgr.h"
-#include "GridNotifiersImpl.h"
 #include "Cell.h"
-#include "CellImpl.h"
-#include "InstanceScript.h"
-#include "ScriptedCreature.h"
 #include "Group.h"
 #include "SmartAI.h"
 #include "ScriptMgr.h"