Provide the now required response object to the smtp exception

mail gem 2.8.0 added ruby 3.1 support[1] which added net-smtp as an explicit gem
dependency because it had recently become an extracted gem.

Previously, we used the ruby stdlib version, which was using gem version 0.1.0
in ruby 2.7.0 and 0.2.1 in ruby 3.0.0.

Starting with net-smtp 0.2.2, the Net::SMTPError types now require a response
object [2] and an optional message. 🤷

[1] https://github.com/mikel/mail/pull/1472/files
[2] https://github.com/ruby/net-smtp/pull/26/files

spec/mailers/generic_mailer_spec.rb

@@ -48,7 +48,7 @@
       # raises error when delivered
       msg = @args.merge(:to => 'me@bedrock.gov, you@bedrock.gov')
       notification = GenericMailer.generic_notification(msg)
-      allow(notification).to receive(:deliver_now).and_raise(Net::SMTPFatalError)
+      allow(notification).to receive(:deliver_now).and_raise(Net::SMTPFatalError.new("fake_response"))
 
       # send error msg first...
       expect(GenericMailer)