chore: upgrade rails to 7.0 and other dependencies

app/controllers/application_controller.rb

@@ -109,7 +109,8 @@ class ApplicationController < ActionController::Base
       auth_session.invalidate!
       reset_session
     end
-    Authie::Session.start(self, user: user)
+
+    create_auth_session(user)
     @current_user = user
   end
 

app/controllers/messages_controller.rb

@@ -19,7 +19,7 @@ class MessagesController < ApplicationController
         @message.from = "test@#{domain.name}"
       end
     end
-    @message.subject = "Test Message at #{Time.zone.now.to_s(:long)}"
+    @message.subject = "Test Message at #{Time.zone.now.to_fs(:long)}"
     @message.plain_body = "This is a message to test the delivery of messages through Postal."
   end