feat(nextjs): Check for Vercel Edge Function GA

[lforst]

Vercel Edge Functions GA'd which means the check for "experimental-edge" doesn't always work anymore. Luckily Next.js provides us with a magic string we can use instead (EdgeRuntime).

[github-actions]

size-limit report 📦

Path	Size
@sentry/browser - ES5 CDN Bundle (gzipped + minified)	19.78 KB (-0.01% 🔽)
@sentry/browser - ES5 CDN Bundle (minified)	61.27 KB (0%)
@sentry/browser - ES6 CDN Bundle (gzipped + minified)	18.57 KB (+0.02% 🔺)
@sentry/browser - ES6 CDN Bundle (minified)	54.8 KB (0%)
@sentry/browser - Webpack (gzipped + minified)	20.34 KB (0%)
@sentry/browser - Webpack (minified)	66.48 KB (0%)
@sentry/react - Webpack (gzipped + minified)	20.36 KB (0%)
@sentry/nextjs Client - Webpack (gzipped + minified)	47.57 KB (0%)
@sentry/browser + @sentry/tracing - ES5 CDN Bundle (gzipped + minified)	26.76 KB (+0.01% 🔺)
@sentry/browser + @sentry/tracing - ES6 CDN Bundle (gzipped + minified)	25.19 KB (-0.01% 🔽)
@sentry/replay ES6 CDN Bundle (gzipped + minified)	41.89 KB (+0.03% 🔺)
@sentry/replay - Webpack (gzipped + minified)	38.12 KB (+0.02% 🔺)