[test] Fix console warning in browser test on React 18

[LukasTy]

Follow-up on #16266.

Fixes the failing browser test pipeline on React 18 (eg.: https://app.circleci.com/pipelines/github/mui/mui-x/79592/workflows/0e381e70-f05e-4df4-bb91-4b1dfd522d7e/jobs/453295).

Setting the rowCount on the expected object solves the issue.

[mui-bot]

Deploy preview: https://deploy-preview-16378--material-ui-x.netlify.app/

Generated by 🚫 dangerJS against 32c35a5

[arminmeh]

I have updated this test here #16101
and will merge it today
there are no baselineProps anymore 🙂

let's see if the problem is still there after merge

[LukasTy]

let's see if the problem is still there after merge

Ok, thanks for letting me know. 👌
I've ran CI on React 18 on this branch and it looks golden. 👌

[github-actions]

This pull request has conflicts, please resolve those before we can evaluate the pull request.

[LukasTy]

I have updated this test here #16101
and will merge it today
there are no baselineProps anymore 🙂

@arminmeh , I assume you did not run tests on React 18 before merging? 🙈
https://app.circleci.com/pipelines/github/mui/mui-x/79788/workflows/31243fb9-6369-4644-81eb-9e8fa88f6ba2

[arminmeh]

Missread the

I've ran CI on React 18 on this branch and it looks golden

as
I've ran CI on React 18 on the branch and it looks golden 🤦🏻‍♂️

I will check it out and make another PR with R18 fix

[arminmeh]

#16386