Revert AdyenPaymentMethod#cancel! method signature

[spaghetticode]

The method signature was originally changed in #15 that made the extension compatible with Ruby 3.x.

The previous version is compatible with Ruby 3.x, while the new one was not equivalent to the old one as it requires the second param, which is irrelevant in the context of the method, to be present.

The new signature poses an issues at least on Rowan, as it prevents payments to be cancelled. This is from Rowan staging:

Spree::Order.find_by(number: 'KR700391505').payments.first.cancel!
D, [2024-06-13T08:17:47.239828 #2] DEBUG -- :   TRANSACTION (1.1ms)  ROLLBACK
/app/vendor/bundle/ruby/3.0.0/bundler/gems/solidus-adyen-f654fd0d419c/app/models/concerns/spree/payment_method/adyen_payment_method.rb:41:in `cancel': wrong number of arguments (given 1, expected 2) (ArgumentError)

[cjreeve]

I haven't noticed an error on WATG for this and we appear to be using the code. I don't know about the possible impact this change could have. Hopefully @MadelineCollier will remember previous issue and have an idea if something else is needed.

[MadelineCollier]

Approved as I understand the general gist of the change and how the Ruby 3x work altered the method signature, however this change definitely requires manual testing across all the stores to ensure this:

a) Fixes the issue on Rowan
b) Doesn't introduce new errors for the other brands.

Thanks for taking this on :)