fix: Prepares for IPooledEnumerable removal (#1548)

### Summary

- Removes `IPooledEnumerable` (non-generic)
- Changes `IPooledEnumerable<T>` so that  `Free()` is replaced with the `IDisposable` pattern

Projects/UOContent/Spells/Fourth/ArchProtection.cs

@@ -59,8 +59,6 @@ namespace Server.Spells.Fourth
                     }
                 }
 
-                eable.Free();
-
                 if (Core.AOS)
                 {
                     var party = Party.Get(Caster);