Replace set with let_it_be in spec/policies

Removes usage of `set` in specs

spec/policies/application_setting/term_policy_spec.rb

@@ -5,7 +5,7 @@ require 'spec_helper'
 describe ApplicationSetting::TermPolicy do
   include TermsHelper
 
-  set(:term) { create(:term) }
+  let_it_be(:term) { create(:term) }
   let(:user) { create(:user) }
 
   subject(:policy) { described_class.new(user, term) }

spec/policies/ci/pipeline_schedule_policy_spec.rb

@@ -3,9 +3,9 @@
 require 'spec_helper'
 
 describe Ci::PipelineSchedulePolicy, :models do
-  set(:user) { create(:user) }
-  set(:project) { create(:project, :repository) }
-  set(:pipeline_schedule) { create(:ci_pipeline_schedule, :nightly, project: project) }
+  let_it_be(:user) { create(:user) }
+  let_it_be(:project) { create(:project, :repository) }
+  let_it_be(:pipeline_schedule, reload: true) { create(:ci_pipeline_schedule, :nightly, project: project) }
 
   let(:policy) do
     described_class.new(user, pipeline_schedule)

spec/policies/project_policy_spec.rb

@@ -5,12 +5,12 @@ require 'spec_helper'
 describe ProjectPolicy do
   include ExternalAuthorizationServiceHelpers
   include_context 'ProjectPolicy context'
-  set(:guest) { create(:user) }
-  set(:reporter) { create(:user) }
-  set(:developer) { create(:user) }
-  set(:maintainer) { create(:user) }
-  set(:owner) { create(:user) }
-  set(:admin) { create(:admin) }
+  let_it_be(:guest) { create(:user) }
+  let_it_be(:reporter) { create(:user) }
+  let_it_be(:developer) { create(:user) }
+  let_it_be(:maintainer) { create(:user) }
+  let_it_be(:owner) { create(:user) }
+  let_it_be(:admin) { create(:admin) }
   let(:project) { create(:project, :public, namespace: owner.namespace) }
 
   let(:base_guest_permissions) do

spec/policies/resource_label_event_policy_spec.rb

@@ -3,10 +3,10 @@
 require 'spec_helper'
 
 describe ResourceLabelEventPolicy do
-  set(:user) { create(:user) }
-  set(:project) { create(:project, :private) }
-  set(:issue) { create(:issue, project: project) }
-  set(:private_project) { create(:project, :private) }
+  let_it_be(:user) { create(:user) }
+  let_it_be(:project) { create(:project, :private) }
+  let_it_be(:issue) { create(:issue, project: project) }
+  let_it_be(:private_project) { create(:project, :private) }
 
   describe '#read_resource_label_event' do
     context 'with non-member user' do