Misc cleanups

Source/Game/Arenas/Zones/DalaranSewers.cs

@@ -153,8 +153,6 @@ namespace Game.Arenas
                 }
             });
         }
-
-        EventMap _events = new();
     }
 
     struct DalaranSewersEvents

Source/Game/Arenas/Zones/RingofValor.cs

@@ -177,8 +177,6 @@ namespace Game.Arenas
                 }
             }
         }
-
-        EventMap _events;
     }
 
     struct RingofValorEvents

Source/Game/Entities/Player/Player.Quest.cs

@@ -15,7 +15,6 @@ using Game.Spells;
 using System;
 using System.Collections.Generic;
 using System.Linq;
-using System;
 
 namespace Game.Entities
 {

Source/Game/Quest/QuestObjectiveCriteriaManager.cs

@@ -290,7 +290,7 @@ namespace Game
             return Global.CriteriaMgr.GetQuestObjectiveCriteriaByType(type);
         }
 
-        public bool RequiredAchievementSatisfied(uint achievementId)
+        public override bool RequiredAchievementSatisfied(uint achievementId)
         {
             return _owner.HasAchieved(achievementId);
         }

Source/Game/Spells/SpellCastRequest.cs

@@ -26,7 +26,7 @@ namespace Game.Spells
         public ObjectGuid CastingUnitGUID;
         public SpellCastRequestItemData ItemData;
 
-        public SpellCastRequest(SpellCastRequestPkt castRequest, ObjectGuid castingUnitGUID, SpellCastRequestItemData? itemData = null)
+        public SpellCastRequest(SpellCastRequestPkt castRequest, ObjectGuid castingUnitGUID, SpellCastRequestItemData itemData = null)
         {
             CastRequest = castRequest;
             CastingUnitGUID = castingUnitGUID;