Make ArgumentsInstance internal (#1594)

Jint/Native/Argument/ArgumentsInstance.cs

@@ -13,7 +13,7 @@ namespace Jint.Native.Argument
     /// <summary>
     /// http://www.ecma-international.org/ecma-262/5.1/#sec-10.6
     /// </summary>
-    public sealed class ArgumentsInstance : ObjectInstance
+    internal sealed class ArgumentsInstance : ObjectInstance
     {
         // cache property container for array iteration for less allocations
         private static readonly ThreadLocal<HashSet<string>> _mappedNamed = new(() => new HashSet<string>());