Cannot use `dont-cleanup-after-each` in browser

• @testing-library/react version: 13.3.0
• Testing Framework and version: Storybook 6.5.9
• DOM Environment: Browser

Relevant code or config:

import '@testing-library/react/dont-cleanup-after-each';

What you did:

I'm trying to update to react 18, but am getting errors about act not being available in production builds of react. So, I tried setting globalThis.IS_REACT_ACT_ENVIRONMENT = false, but found that this library automatically sets it to true, so to disable it I tried to import dont-cleanup-after-each as instructed in https://testing-library.com/docs/react-testing-library/setup#skipping-auto-cleanup, since https://github.com/testing-library/react-testing-library/pull/994 said to disable it the same way as cleanup.

What happened:

Uncaught ReferenceError: process is not defined
    at dont-cleanup-after-each.js:1:1

This is because process does not exist in browsers, which is where I'm running RTL.

Reproduction:

Problem description:

I can't disable the use of ACT, it seems, which causes my tests to fail.

Suggested solution:

If process is not defined, you could check for import.meta.env and use that instead.

Start by inspecting dont-cleanup-after-each.js and the browser setup described in the issue; verify why it references process when loaded outside Node. Reproduce the failure in a browser-based test setup, then confirm that disabling cleanup and the related ACT behavior works without the ReferenceError.