C# 9 Cleanup (#325)

- [X] Removes EventArgs - not needed
- [X] Merges sequential checks
- [X] Removes redundant type declarations

Projects/UOContent/Engines/ConPVP/DuelContext.cs

@@ -29,7 +29,7 @@ namespace Server.Engines.ConPVP
         private static readonly TimeSpan CombatDelay = TimeSpan.FromSeconds(30.0);
         private static readonly TimeSpan AutoTieDelay = TimeSpan.FromMinutes(15.0);
 
-        private readonly List<Item> m_Walls = new List<Item>();
+        private readonly List<Item> m_Walls = new();
 
         private Timer m_AutoTieTimer;