Core/Spells: move Cannibalize and Carrion Feeder cast checks to SpellScripts.

src/server/game/Spells/SpellEffects.cpp

@@ -816,10 +816,6 @@ void Spell::EffectDummy(SpellEffIndex effIndex)
                     }
                     return;
                 }
-                case 20577:                                 // Cannibalize
-                    if (unitTarget)
-                        m_caster->CastSpell(m_caster, 20578, false, NULL);
-                    return;
                 case 23019:                                 // Crystal Prison Dummy DND
                 {
                     if (!unitTarget || !unitTarget->isAlive() || unitTarget->GetTypeId() != TYPEID_UNIT || unitTarget->ToCreature()->isPet())