Implement interfaces in the non-generic enumerator base (#82923)

* Implement IDisposable in the non-generic enumerator base

...so that the interface implementation details go to the non-generic dispatch map.

Saves 1.5 kB on BasicMinimalApi.

* f

src/libraries/System.Private.CoreLib/src/System/Array.Enumerators.cs

@@ -67,7 +67,7 @@ public void Reset()
         }
     }
 
-    internal abstract class SZGenericArrayEnumeratorBase
+    internal abstract class SZGenericArrayEnumeratorBase : IDisposable
     {
         protected readonly Array _array;
         protected int _index;
@@ -141,7 +141,7 @@ public T Current
         object? IEnumerator.Current => Current;
     }
 
-    internal abstract class GenericEmptyEnumeratorBase
+    internal abstract class GenericEmptyEnumeratorBase : IDisposable, IEnumerator
     {
 #pragma warning disable CA1822 // https://github.com/dotnet/roslyn-analyzers/issues/5911
         public bool MoveNext() => false;