Swap FK ci_freeze_periods to projects for LFK

Removes FK for ci_freeze_periods to projects

Changelog: changed

db/post_migrate/20220113013319_remove_projects_ci_freeze_periods_project_id_fk.rb

+# frozen_string_literal: true
+
+class RemoveProjectsCiFreezePeriodsProjectIdFk < Gitlab::Database::Migration[1.0]
+  disable_ddl_transaction!
+
+  def up
+    with_lock_retries do
+      remove_foreign_key_if_exists(:ci_freeze_periods, :projects, name: "fk_2e02bbd1a6")
+    end
+  end
+
+  def down
+    add_concurrent_foreign_key(:ci_freeze_periods, :projects, name: "fk_2e02bbd1a6", column: :project_id, target_column: :id, on_delete: "cascade")
+  end
+end

db/schema_migrations/20220113013319

+ccfbbbe52b27833453f867c4d7093187d21dbbfebe054b366ff010c54de50974
\ No newline at end of file

db/structure.sql

@@ -29171,9 +29171,6 @@ ALTER TABLE ONLY agent_group_authorizations
 ALTER TABLE ONLY deployment_approvals
     ADD CONSTRAINT fk_2d060dfc73 FOREIGN KEY (deployment_id) REFERENCES deployments(id) ON DELETE CASCADE;
 
-ALTER TABLE ONLY ci_freeze_periods
-    ADD CONSTRAINT fk_2e02bbd1a6 FOREIGN KEY (project_id) REFERENCES projects(id) ON DELETE CASCADE;
-
 ALTER TABLE ONLY notes
     ADD CONSTRAINT fk_2e82291620 FOREIGN KEY (review_id) REFERENCES reviews(id) ON DELETE SET NULL;
 

lib/gitlab/database/gitlab_loose_foreign_keys.yml

+---
 dast_site_profiles_pipelines:
   - table: ci_pipelines
     column: ci_pipeline_id
@@ -34,6 +35,10 @@ ci_daily_build_group_report_results:
   - table: namespaces
     column: group_id
     on_delete: async_delete
+ci_freeze_periods:
+  - table: projects
+    column: project_id
+    on_delete: async_delete
 ci_pending_builds:
   - table: namespaces
     column: namespace_id

spec/models/ci/freeze_period_spec.rb

@@ -5,6 +5,11 @@ require 'spec_helper'
 RSpec.describe Ci::FreezePeriod, type: :model do
   subject { build(:ci_freeze_period) }
 
+  it_behaves_like 'cleanup by a loose foreign key' do
+    let!(:parent) { create(:project) }
+    let!(:model) { create(:ci_freeze_period, project: parent) }
+  end
+
   let(:invalid_cron) { '0 0 0 * *' }
 
   it { is_expected.to belong_to(:project) }