This is follow-up of introducing the ability to sort security listeners, which was introduced in #37337. Part of the discussion at that time was whether we'd still need to hardcoded sorting algorithm in the Firewall class, which was previously needed to sort in the LogoutListener at the correct position. With the ability to sort by a priority that was actually no longer needed.

I had this change temporarily implemented in 1972786, though in the discussion it was decided against and instead keep the code for backwards compatibility reasons. Otherwise we'd need to declare a conflict with security-bundle in the composer.json and it was argued by @chalasr against making the security component aware of security-bundle (see #37337 (comment)).

Though I've recognized, things have changed in the meantime, and security component is now declaring conflict for security-bundle (introduced by @nicolas-grekas in 314ef9f)

So I want to give this another shot and clean up the Firewall class, targeting potentially the 5.4 branch, definitely for the 6.0 branch.

Considerations
To make the clean-up work, the LogoutListener service needs to be added to the list of listeners generated by SecurityExtension. Until now, it's intentionally (?) left out. In the 5.4 branch this could be considered a breaking change. Let me know what you think, if this is in fact considered as breaking, I'm happy to change the target to 6.0.