fix(utils): Fix XHR instrumentation early return

[mydea]

This was introduced in #9542 😬

Ideally we could have a lint rule for this, but probably this is rather hard to do - so reminder to self to keep an eye out for this in the future!

Closes #9747

Note to reviewer(s): could you double check the file to make sure I didn't miss anything again? Just being cautious there...

[lforst]

looks right

[github-actions]

size-limit report 📦

Path	Size
@sentry/browser (incl. Tracing, Replay, Feedback) - Webpack (gzipped)	74.66 KB (+0.02% 🔺)
@sentry/browser (incl. Tracing, Replay) - Webpack (gzipped)	66 KB (+0.01% 🔺)
@sentry/browser (incl. Tracing, Replay) - Webpack with treeshaking flags (gzipped)	59.6 KB (+0.01% 🔺)
@sentry/browser (incl. Tracing) - Webpack (gzipped)	31.13 KB (+0.03% 🔺)
@sentry/browser (incl. Feedback) - Webpack (gzipped)	29.74 KB (+0.04% 🔺)
@sentry/browser - Webpack (gzipped)	21.39 KB (+0.03% 🔺)
@sentry/browser (incl. Tracing, Replay, Feedback) - ES6 CDN Bundle (gzipped)	71.25 KB (+0.02% 🔺)
@sentry/browser (incl. Tracing, Replay) - ES6 CDN Bundle (gzipped)	62.97 KB (+0.02% 🔺)
@sentry/browser (incl. Tracing) - ES6 CDN Bundle (gzipped)	29.65 KB (+0.03% 🔺)
@sentry/browser - ES6 CDN Bundle (gzipped)	21.71 KB (+0.03% 🔺)
@sentry/browser (incl. Tracing, Replay) - ES6 CDN Bundle (minified & uncompressed)	198.35 KB (+0.02% 🔺)
@sentry/browser (incl. Tracing) - ES6 CDN Bundle (minified & uncompressed)	89.78 KB (+0.04% 🔺)
@sentry/browser - ES6 CDN Bundle (minified & uncompressed)	64.76 KB (+0.05% 🔺)
@sentry/browser (incl. Tracing) - ES5 CDN Bundle (gzipped)	32.3 KB (+0.03% 🔺)
@sentry/react (incl. Tracing, Replay) - Webpack (gzipped)	66.36 KB (+0.01% 🔺)
@sentry/react - Webpack (gzipped)	21.43 KB (+0.03% 🔺)
@sentry/nextjs Client (incl. Tracing, Replay) - Webpack (gzipped)	83.09 KB (+0.02% 🔺)
@sentry/nextjs Client - Webpack (gzipped)	48.23 KB (+0.02% 🔺)
@sentry-internal/feedback - Webpack (gzipped)	16.19 KB (0%)

[Lms24]

Checked and didn't find other similar early returns.

Yeah I guess we can't lint on returning void in a function that should return void 🤔