CallbackRegistry.disconnect allows directly callbacks by function

CallbackRegistry now allows directly passing a function and optionally signal to disconnect instead of needing to track the callback ID returned by connect.

from matplotlib.cbook import CallbackRegistry

def my_callback(event):
    print(event)

callbacks = CallbackRegistry()
callbacks.connect('my_signal', my_callback)

# Disconnect by function reference instead of callback ID
callbacks.disconnect('my_signal', my_callback)