Fix tests for activerecord main branch

Rails changed what it prints in `inspect` method (rails/rails#49765).
Only `id` is printed by default.

test/dummy/app/controllers/users_controller.rb

@@ -19,7 +19,7 @@ def action2
   # Single record with all used columns.
   def action3
     user = User.first
-    user.inspect
+    user.attributes
     head :ok
   end
 

test/dummy/app/jobs/used_job.rb

@@ -2,6 +2,6 @@
 
 class UsedJob < ActiveJob::Base
   def perform
-    User.first.inspect
+    User.first.attributes
   end
 end

test/dummy/app/mailers/user_mailer.rb

@@ -14,7 +14,7 @@ def unused_fields_email
 
   def used_fields_email
     user = params[:user]
-    _projects = Project.all.map(&:inspect)
+    _projects = Project.all.map(&:attributes)
 
     mail(to: user.email) do |format|
       format.text { render plain: "Text" }