Improve NextJS integration tests

[AbhiPrasad]

Problem Statement

NextJS integration tests are definitely our most flaky set of tests, and they are also much harder to debug since they don't use jest under the hood.

https://sentry.io/organizations/sentry/dashboard/24245/?project=5899451&statsPeriod=3d

We should update these tests!

Solution Brainstorm

These probably involves a couple of changes:

• Instead of using puppeteer, use playwright like our browser and remix integration tests. This is as puppeteer causes some problems for fresh installations, which was ran into by @drguthals here. -> test(nextjs): Migrate Next SDK's client side tests to Playwright. #6718
• Use jest for the node integration tests, like our remix integration tests do. This should make things much more consistent -> test(nextjs): Refactor server-side integration tests #6909
• Figure out how to make session tests less flaky
• Rewrite main test script in TS rather than bash
• Run most recent node version integration test on Windows

[lobsterkatie]

Before we move more tests to playwright, I'd like us to spend some time figuring out how to debug them in VSCode. I've tried, but have yet to make it work successfully.

[onurtemizkan]

Before we move more tests to playwright, I'd like us to spend some time figuring out how to debug them in VSCode. I've tried, but have yet to make it work successfully.

@lobsterkatie - After several failed attempts with launch.json, I was able to debug Next client-side tests using https://github.com/microsoft/playwright-vscode extension. It's not perfect though, for example, it doesn't fully support webServer config in playwright.config.ts. I'll continue trying to figure out how to make it work with launch.json. But we have a working alternative for the time being.

[HazAT]

Closing in favor of #6906