Replace set to let_it_be in spec/services

Get rids of `set` in specs

spec/services/ci/create_pipeline_service/parent_child_pipeline_spec.rb

@@ -3,8 +3,8 @@
 require 'spec_helper'
 
 describe Ci::CreatePipelineService, '#execute' do
-  set(:project) { create(:project, :repository) }
-  set(:user) { create(:user) }
+  let_it_be(:project) { create(:project, :repository) }
+  let_it_be(:user) { create(:user) }
   let(:ref_name) { 'master' }
 
   let(:service) do

spec/services/ci/pipeline_processing/atomic_processing_service/status_collection_spec.rb

@@ -5,12 +5,12 @@ require 'spec_helper'
 describe Ci::PipelineProcessing::AtomicProcessingService::StatusCollection do
   using RSpec::Parameterized::TableSyntax
 
-  set(:pipeline) { create(:ci_pipeline) }
-  set(:build_a) { create(:ci_build, :success, name: 'build-a', stage: 'build', stage_idx: 0, pipeline: pipeline) }
-  set(:build_b) { create(:ci_build, :failed, name: 'build-b', stage: 'build', stage_idx: 0, pipeline: pipeline) }
-  set(:test_a) { create(:ci_build, :running, name: 'test-a', stage: 'test', stage_idx: 1, pipeline: pipeline) }
-  set(:test_b) { create(:ci_build, :pending, name: 'test-b', stage: 'test', stage_idx: 1, pipeline: pipeline) }
-  set(:deploy) { create(:ci_build, :created, name: 'deploy', stage: 'deploy', stage_idx: 2, pipeline: pipeline) }
+  let_it_be(:pipeline) { create(:ci_pipeline) }
+  let_it_be(:build_a) { create(:ci_build, :success, name: 'build-a', stage: 'build', stage_idx: 0, pipeline: pipeline) }
+  let_it_be(:build_b) { create(:ci_build, :failed, name: 'build-b', stage: 'build', stage_idx: 0, pipeline: pipeline) }
+  let_it_be(:test_a) { create(:ci_build, :running, name: 'test-a', stage: 'test', stage_idx: 1, pipeline: pipeline) }
+  let_it_be(:test_b) { create(:ci_build, :pending, name: 'test-b', stage: 'test', stage_idx: 1, pipeline: pipeline) }
+  let_it_be(:deploy) { create(:ci_build, :created, name: 'deploy', stage: 'deploy', stage_idx: 2, pipeline: pipeline) }
 
   let(:collection) { described_class.new(pipeline) }
 

spec/services/metrics/dashboard/clone_dashboard_service_spec.rb

@@ -7,9 +7,9 @@ describe Metrics::Dashboard::CloneDashboardService, :use_clean_rails_memory_stor
 
   STAGES = ::Gitlab::Metrics::Dashboard::Stages
 
-  set(:user) { create(:user) }
-  set(:project) { create(:project, :repository) }
-  set(:environment) { create(:environment, project: project) }
+  let_it_be(:user) { create(:user) }
+  let_it_be(:project) { create(:project, :repository) }
+  let_it_be(:environment) { create(:environment, project: project) }
 
   describe '#execute' do
     subject(:service_call) { described_class.new(project, user, params).execute }