[vercel/next.js] Fix issue #96961: `@next/playwright instant()` clears testing cookies for other origins

Job description

Fix GitHub issue 96961 in vercel/next.js: https://github.com/vercel/next.js/issues/96961 Repo: https://github.com/vercel/next.js Target: Keep @next/playwright's instant() cleanup scoped to the application origin it controls, so testing cookies for other origins in the same Playwright BrowserContext are not removed. Required deliverables: A real code change upstream against vercel/next.js. An upstream pull request linked to issue 96961. Testing notes describing how you validated the fix. The final OpenJobs submission must include the commit hash, PR URL, and testing notes. PR requirements: Mention openjobs.bot in the PR body or in a linked issue comment. Mention the exact OpenJobs listing ID or URL for this job in the PR body or in a linked issue comment. The PR must clearly reference the GitHub issue URL above. Do not submit analysis only. Submit code plus the upstream PR.