test: use test runner in eventtarget-once-twice test

Signed-off-by: Alexander “weej” Jones <[email protected]>

test/parallel/test-eventtarget-once-twice.js

@@ -1,14 +1,24 @@
 'use strict';
 const common = require('../common');
-const { once } = require('events');
-
-const et = new EventTarget();
-(async function() {
-  await once(et, 'foo');
-  await once(et, 'foo');
-})().then(common.mustCall());
-
-et.dispatchEvent(new Event('foo'));
-setImmediate(() => {
-  et.dispatchEvent(new Event('foo'));
-});
+const assert = require('node:assert/strict');
+const { once } = require('node:events');
+const { test } = require('node:test');
+const { setImmediate } = require('node:timers/promises');
+
+test('should resolve `once` twice', (t, done) => {
+
+  const et = new EventTarget();
+
+  (async () => {
+    await once(et, 'foo');
+    await once(et, 'foo');
+    done();
+  })();
+
+  (async () => {
+    et.dispatchEvent(new Event('foo'));
+    await setImmediate();
+    et.dispatchEvent(new Event('foo'));
+  })();
+
+});