[BUG] Telegram classes with no custom __init__ are not frozen by default #3452
Description
Steps to Reproduce
- Initialize a class with no overriden
__init__, e.g.VideoChatStarted - do
VideoChatStarted().api_kwargs = "something"
Expected behaviour
AttributeError should be raised
Actual behaviour
The attribute is set successfully.
Operating System
OS-agnostic
Version of Python, python-telegram-bot & dependencies
Python version agnostic
PTB - 20.0b0Relevant log output
No response
Additional Context
No response