Clicking an IconButton without on_click results in an error

[iisakkirotko]

Expected Behavior

Clicking the button does nothing.

Current Behavior

Clicking the button throws an error:

Traceback (most recent call last):
  File "/Users/iisakki/micromamba/envs/env/lib/python3.10/site-packages/reacton/ipyvue.py", line 23, in handler
    callback_ref.current(*args)
  File "/Users/iisakki/micromamba/envs/env/lib/python3.10/site-packages/solara/components/button.py", line 84, in <lambda>
    ipyvue.use_event(btn, click_event, lambda *_ignore: on_click and on_click())
  File "/Users/iisakki/micromamba/envs/env/lib/python3.10/typing.py", line 957, in __call__
    result = self.__origin__(*args, **kwargs)
TypeError: Can't instantiate abstract class Callable with abstract method __call__
This website runs on [Solara](https://solara.dev/)

Steps to Reproduce the Problem

See this PyCafe snippet

Specifications

• Solara Version: 1.50.0
• Platform: MacOS
• Affected Python Versions: at least 3.10, probably all.