Extension binder fails to resolve overloads with nested generics

[slozier]

For example, in .NET 8 the following overload is added:

public static Dictionary<TKey,TValue> ToDictionary<TKey,TValue> (this IEnumerable<KeyValuePair<TKey,TValue>> source);

Since PythonDictionary is an IEnumerable<KeyValuePair<object, object>> the extension method should be callable:

import clr
clr.AddReference("System.Linq")
from System.Linq import Enumerable
clr.ImportExtensions(Enumerable)
{}.ToDictionary()

This causes an assertion error when running test_cliclass.test_extension_methods in Debug mode.