Remove obsolete new_session helper

After #44748, the `new_session` helper no longer takes a block and is
the same as calling `app(true)`. Therefore, I think there's no reason to
expose it to Rails console users.

railties/CHANGELOG.md

@@ -11,9 +11,9 @@
 
 *   Implement Rails console commands and helpers with IRB v1.13's extension APIs
 
-    Rails console users will now see `helper`, `controller`, `new_session`, and `app` under
-    IRB help message's `Helper methods` category. And `reload!` command will be displayed under
-    the new `Rails console` commands category.
+    Rails console users will now see `helper`, `controller`, and `app` under IRB help message's
+    `Helper methods` category. And `reload!` command will be displayed under the new
+    `Rails console` commands category.
 
     Prior to this change, Rails console's commands and helper methods are added through IRB's
     private components and don't show up in its help message, which led to poor discoverability.

railties/lib/rails/commands/console/irb_console.rb

@@ -27,14 +27,6 @@ def execute
       end
     end
 
-    class NewSession < RailsHelperBase
-      description "Creates a new ActionDispatch::Integration::Session. If a block is given, the new session will be yielded to it."
-
-      def execute
-        new_session
-      end
-    end
-
     class AppInstance < RailsHelperBase
       description "Creates a new ActionDispatch::Integration::Session and memoizes it. Use `app(true)` to create a new instance."
 
@@ -56,7 +48,6 @@ def execute(*)
 
     IRB::HelperMethod.register(:helper, ControllerHelper)
     IRB::HelperMethod.register(:controller, ControllerInstance)
-    IRB::HelperMethod.register(:new_session, NewSession)
     IRB::HelperMethod.register(:app, AppInstance)
     IRB::Command.register(:reload!, Reloader)
 

railties/test/application/console_test.rb

@@ -152,12 +152,6 @@ def test_controller_helper_method
     write_prompt "controller.class.name", "ApplicationController"
   end
 
-  def test_new_session_helper_method
-    spawn_console("-e development")
-
-    write_prompt "new_session.class.name", "ActionDispatch::Integration::Session"
-  end
-
   def test_app_helper_method
     app_file "config/routes.rb", <<-RUBY
       Rails.application.routes.draw do