Add index on releases table to resolve cicd settings page timeout

Changelog: performance

db/post_migrate/20220310134207_add_index_project_id_and_released_at_and_id_on_releases.rb

+# frozen_string_literal: true
+
+class AddIndexProjectIdAndReleasedAtAndIdOnReleases < Gitlab::Database::Migration[1.0]
+  INDEX_NAME = 'index_releases_on_project_id_and_released_at_and_id'
+
+  disable_ddl_transaction!
+
+  def up
+    add_concurrent_index :releases, [:project_id, :released_at, :id],
+      name: INDEX_NAME
+  end
+
+  def down
+    remove_concurrent_index_by_name :releases, INDEX_NAME
+  end
+end

db/schema_migrations/20220310134207

+951abe39e4735f0f71ac6ad1701ffa8688dfd82a59b0383d6c55cef8f6de8e7f
\ No newline at end of file

db/structure.sql

@@ -28821,6 +28821,8 @@ CREATE UNIQUE INDEX index_release_links_on_release_id_and_url ON release_links U
 
 CREATE INDEX index_releases_on_author_id_id_created_at ON releases USING btree (author_id, id, created_at);
 
+CREATE INDEX index_releases_on_project_id_and_released_at_and_id ON releases USING btree (project_id, released_at, id);
+
 CREATE INDEX index_releases_on_project_id_and_tag ON releases USING btree (project_id, tag);
 
 CREATE INDEX index_releases_on_released_at ON releases USING btree (released_at);