Copied `delay` utility function into Cypress backend (#18330)

runner to decouple from incoming TS refactors

frontend/test/__runner__/backend.js

@@ -4,7 +4,6 @@ import path from "path";
 import { spawn } from "child_process";
 
 import fetch from "isomorphic-fetch";
-import { delay } from "../../src/metabase/lib/promise";
 
 export const DEFAULT_DB_KEY = "/test_db_fixture.db";
 
@@ -176,3 +175,8 @@ function createSharedResource(
     },
   };
 }
+
+// Copied here from `frontend/src/metabase/lib/promise.js` to decouple Cypress from Typescript
+function delay(duration) {
+  return new Promise((resolve, reject) => setTimeout(resolve, duration));
+}