fix(catalog-backend): add missing JSDoc type annotation on down function

Signed-off-by: Fredrik Adelöw <freben@spotify.com>
Made-with: Cursor

plugins/catalog-backend/migrations/20220116144621_remove_legacy.js

@@ -25,6 +25,9 @@ exports.up = async function up(knex) {
   await knex.schema.dropTable('entities');
 };
 
+/**
+ * @param {import('knex').Knex} knex
+ */
 exports.down = async function down(knex) {
   await knex.schema.createTable('entities', table => {
     table.comment('All entities currently stored in the catalog');