fix(utils): Fix XHR instrumentation early return (#9770)

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

packages/utils/src/instrument/xhr.ts

@@ -46,7 +46,7 @@ export function instrumentXHR(): void {
       const url = parseUrl(args[1]);
 
       if (!method || !url) {
-        return;
+        return originalOpen.apply(this, args);
       }
 
       this[SENTRY_XHR_DATA_KEY] = {
@@ -124,7 +124,7 @@ export function instrumentXHR(): void {
       const sentryXhrData = this[SENTRY_XHR_DATA_KEY];
 
       if (!sentryXhrData) {
-        return;
+        return originalSend.apply(this, args);
       }
 
       if (args[0] !== undefined) {