fix(core,browser): Delete SentryNonRecordingSpan from fetch/xhr map

[github-actions]

Note

The pull request "fix(core,browser): Delete SentryNonRecordingSpan from fetch/xhr map" was created by @JPeer264 but did not reference an issue. Therefore this issue was created for better visibility in external tools like Linear.

This resolves a leak where SentryNonRecordingSpan are pilled up when tracingSampleRate is set to 0. Theoretically SentryNonRecordingSpan are still treated as spans and added to the spans list, but never removed

By moving shouldCreateSpanResult closer to the actual span logic, this is now resolved.

[linear]

JS-1719

[github-actions]

A PR closing this issue has just been released 🚀

This issue was referenced by PR #19336, which was included in the 10.40.0 release.