Remove pipeline_id column from requirements_management_test_reports

Given the feature changes this column is no longer needed.

changelogs/unreleased/issue_34247.yml

+---
+title: Remove pipeline_id column from requirements_test_reports
+merge_request: 38924
+author:
+type: deprecated

db/post_migrate/20200810191256_remove_pipeline_id_from_test_reports.rb

+# frozen_string_literal: true
+
+class RemovePipelineIdFromTestReports < ActiveRecord::Migration[6.0]
+  include Gitlab::Database::MigrationHelpers
+
+  DOWNTIME = false
+
+  def up
+    remove_column :requirements_management_test_reports, :pipeline_id
+  end
+
+  def down
+    add_column :requirements_management_test_reports, :pipeline_id, :integer
+
+    with_lock_retries do
+      # rubocop:disable Migration/AddConcurrentForeignKey
+      add_foreign_key :requirements_management_test_reports, :ci_pipelines, column: :pipeline_id, on_delete: :nullify
+      # rubocop:enable Migration/AddConcurrentForeignKey
+    end
+  end
+end

db/schema_migrations/20200810191256

+66653e275889da8e695843f648af36c8a4e275b4d3215119eab4942db1b4b823
\ No newline at end of file

db/structure.sql

@@ -15102,7 +15102,6 @@ CREATE TABLE public.requirements_management_test_reports (
     id bigint NOT NULL,
     created_at timestamp with time zone NOT NULL,
     requirement_id bigint NOT NULL,
-    pipeline_id bigint,
     author_id bigint,
     state smallint NOT NULL,
     build_id bigint
@@ -20617,8 +20616,6 @@ CREATE INDEX index_requirements_management_test_reports_on_author_id ON public.r
 
 CREATE INDEX index_requirements_management_test_reports_on_build_id ON public.requirements_management_test_reports USING btree (build_id);
 
-CREATE INDEX index_requirements_management_test_reports_on_pipeline_id ON public.requirements_management_test_reports USING btree (pipeline_id);
-
 CREATE INDEX index_requirements_management_test_reports_on_requirement_id ON public.requirements_management_test_reports USING btree (requirement_id);
 
 CREATE INDEX index_requirements_on_author_id ON public.requirements USING btree (author_id);
@@ -22176,9 +22173,6 @@ ALTER TABLE ONLY public.service_desk_settings
 ALTER TABLE ONLY public.group_custom_attributes
     ADD CONSTRAINT fk_rails_246e0db83a FOREIGN KEY (group_id) REFERENCES public.namespaces(id) ON DELETE CASCADE;
 
-ALTER TABLE ONLY public.requirements_management_test_reports
-    ADD CONSTRAINT fk_rails_24cecc1e68 FOREIGN KEY (pipeline_id) REFERENCES public.ci_pipelines(id) ON DELETE SET NULL;
-
 ALTER TABLE ONLY public.cluster_agents
     ADD CONSTRAINT fk_rails_25e9fc2d5d FOREIGN KEY (project_id) REFERENCES public.projects(id) ON DELETE CASCADE;