Revert "Bug Fix: Register Webhook Event Only Once"

[elia]

Reverts solidusio/solidus_stripe#318

Reverting since the CI failed on main, we need to look into this further.

cc @cpfergus1

[cpfergus1]

@elia I found two other ways to fix this, but I am still failing some tests locally and would be interested to see what CI returns (wondering if it is my environment), LMKWYT!

lib/solidus_stripe/webhook/event.rb
       def register(user_events:, bus:, core_events: CORE_EVENTS)
          (core_events + user_events).each do |event|
            if bus.registry.registrations.select { |registration| registration.event_name == :"stripe.#{event}" }.empty? 
              bus.register(:"stripe.#{event}")
            end
          end
        end

lib/solidus_stripe/engine.rb
    initializer "solidus_stripe.pub_sub", after: "spree.core.pub_sub" do |app|
      require "solidus_stripe/webhook/event"

      app.reloader.to_prepare do
        SolidusStripe::Webhook::Event.register(
          user_events: SolidusStripe.configuration.webhook_events,
          bus: Spree::Bus
        )
        SolidusStripe::Webhook::PaymentIntentSubscriber.new.subscribe_to(Spree::Bus)
        SolidusStripe::Webhook::ChargeSubscriber.new.subscribe_to(Spree::Bus)
      end
    end