fix(nextjs): Flush with `waitUntil` in `captureRequestError`#15146

lforst merged 2 commits intodevelopgetsentry/sentry-javascript:developfrom

lforst-capture-request-error-vercel-wait-until-flushgetsentry/sentry-javascript:lforst-capture-request-error-vercel-wait-until-flushCopy head branch name to clipboard