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/Mobiles/Monsters/ML/Humanoid/Magic/InterredGrizzle .cs

@@ -120,7 +120,6 @@ namespace Server.Mobiles
                     var eable = Map.GetItemsInRange<StainedOoze>(p, 0);
                     using var enumerator = eable.GetEnumerator();
                     bool atLocation = enumerator.MoveNext();
-                    eable.Free();
                     if (!atLocation)
                     {
                         break;