Cannot implement an interface that extends another interface #1783

Environment

• Pythonnet version: 3.0.0a2
• Python version: 3.8.10
• Operating System: Ubuntu 20.04.4 LTS (docker run --rm -it ubuntu:20.04)
• .NET Runtime: .NET Core 6.0.202

Details

• Describe what you were trying to get done.

  Attempting to implement interfaces defined in .NET. Works fine for simple interfaces but I receive a weird error when the interface extends IDisposable

• What commands did you run to trigger this issue? If you can provide a
  Minimal, Complete, and Verifiable example
  this will help us understand the issue.

from clr_loader import get_coreclr
rt = get_coreclr("conf.json")
from pythonnet import set_runtime
set_runtime(rt)
import clr

import System
import System.Buffers


class MyDisposable(System.IDisposable):
    __namespace__ = "MyNamespace"

    def Dispose(self) -> None:
        print("Dispose")

md = MyDisposable()
md.Dispose()


class MyBuffer(System.Buffers.IMemoryOwner):
    __namespace__ = "MyNamespace"


    def Dispose(self) -> None:
        print("Dispose")


mb = MyBuffer()
mb.Dispose()    

conf.json:

{
  "runtimeOptions": {
    "tfm": "net6.0",
    "framework": {
      "name": "Microsoft.NETCore.App",
      "version": "6.0.4"
    }
  }
}

• If there was a crash, please include the traceback here.

(venv) root@ca20f043eef5:/t# python demo.py
Dispose
Traceback (most recent call last):
  File "demo.py", line 21, in <module>
    class MyBuffer(System.Buffers.IMemoryOwner):
TypeError: Method 'Dispose' in type 'MyNamespace.MyBuffer' from assembly 'Python.Runtime.Dynamic, Version=0.0.0.0, Culture=neutral, PublicKeyToken=null' does not have an implementation.