[BUG]: debounce_timeout compare different iterators

[wennmbj]

vSomeip Version

v3.4.10

Boost Version

1.74

Environment

Ubuntu 22.04

Describe the bug

In function: routing_manager_base::debounce_timeout_update_cbk the if condition: if (_event && (_event->get_subscribers().find(_client) != _event->get_subscribers().end()) && _filter) does not work properly. Here get_subscribers() return a copy of a set with each call. So the objects will never be equal here _event->get_subscribers().find(_client) != _event->get_subscribers().end())
My PR: #739 fixes the issue, but get_subscribers() should be refactored to return a reference instead a copy.

Reproduction Steps

No response

Expected behaviour

No response

Logs and Screenshots

No response

[wennmbj]

Pull request will be closed since this change will be added here: 2ad557f