Add passkey keyword parameter to PasskeyAuthenticatable.after_passkey_authentication

[tcannonfodder]

To make the callback more useful, it should include the passkey that was used to authenticate.

This would make it easier to perform actions like:

• Notifying the user that a new authentication occurred (and which passkey was used)
• Updating some app-specific data related to the passkey

So the new method signature should be:

def after_passkey_authentication(passkey:)
...
end