Symfony version(s) affected: 4.4.30

Description
The Symfony profiler "Performance" section does not display any timing events.

How to reproduce

Update to symfony/http-kernel 4.4.30

Possible Solution
Hotfix: Replace Symfony\Component\HttpKernel\Debug\TraceableEventDispatcher with file of release 4.4.29

I assume the problem is the changed method to identify a running stopwatch section introduced in #42331

I have to confess, I did not dig too deep into the Code, but I assume there are stopwatch sections created with the X-Debug-Token as identifier which never get stopped again, thus there is no timing information in the profiler. But as I said, just an assumption.

Additional context
As far as I researched, there are no other problems with this PR and I only noticed that the performance metrics are affected.