Merge pull request #16366 from Automattic/copilot/fix-github-actions-job-node-18-mongodb-7-0-7

fix: await post.populate() in test to prevent dangling promise on Node 18

Author: vkarpov15

test/document.populate.test.js

@@ -205,7 +205,7 @@ describe('document.populate', function() {
     param.select = '-email';
     param.options = { sort: 'name' };
     param.path = '_creator';
-    post.populate(param);
+    await post.populate(param);
     param.path = 'fans';
 
     await p.populate(param);