Event processor migration: Browser profiling thread attributes assignment

[Lms24]

packages/browser/src/profiling/integration.ts

attachProfiledThreadToEvent itself is easy to port but it asserts on the profiling context being set on the event. We need some other way to decide if a span should receive the attributes (thread.id, thread.name)

[linear-code]

JS-2216

[github-actions]

A PR closing this issue has just been released 🚀

This issue was referenced by PR #20800, which was included in the 10.53.0 release.