fix(nextjs): Make withSentryConfig isomorphic

[lforst]

Fixes #5511

[github-actions]

size-limit report 📦

Path	Size
@sentry/browser - ES5 CDN Bundle (gzipped + minified)	21.04 KB (+0.07% 🔺)
@sentry/browser - ES5 CDN Bundle (minified)	65.68 KB (+0.09% 🔺)
@sentry/browser - ES6 CDN Bundle (gzipped + minified)	19.59 KB (+0.12% 🔺)
@sentry/browser - ES6 CDN Bundle (minified)	58.15 KB (+0.12% 🔺)
@sentry/browser - Webpack (gzipped + minified)	21.2 KB (+0.16% 🔺)
@sentry/browser - Webpack (minified)	69.07 KB (+0.05% 🔺)
@sentry/react - Webpack (gzipped + minified)	21.22 KB (+0.16% 🔺)
@sentry/nextjs Client - Webpack (gzipped + minified)	49.16 KB (+0.09% 🔺)
@sentry/browser + @sentry/tracing - ES5 CDN Bundle (gzipped + minified)	28.67 KB (+0.1% 🔺)
@sentry/browser + @sentry/tracing - ES6 CDN Bundle (gzipped + minified)	26.9 KB (+0.1% 🔺)
@sentry/replay ES6 CDN Bundle (gzipped + minified)	48.24 KB (+1.32% 🔺)
@sentry/replay - Webpack (gzipped + minified)	42.1 KB (+1.53% 🔺)
@sentry/browser + @sentry/tracing + @sentry/replay - ES6 CDN Bundle (gzipped + minified)	67.21 KB (+1.07% 🔺)
@sentry/browser + @sentry/replay - ES6 CDN Bundle (gzipped + minified)	60.11 KB (+1.23% 🔺)

[Lms24]

Just to confirm: We don't need the pass-through function in server/index.ts?

[lforst]

Just to confirm: We don't need the pass-through function in server/index.ts?

@Lms24 There it is exported from ./config anyhow. Server code is not bundled (and implicitly not multiplexed) so this file is gonna stay the same in any case.