I could not identify the commit that changes this behavior but
it is reproducible on our bigboxes and my arch system.

The tests may fail when repeated because the listener may bind to fast
to the tcp tuple again. This is fixed by using SO_REUSEPORT instead of SO_REUSEADDR.

TIL: SO_REUSEADDR is about address wildcards and SO_REUSEPORT allows
binding to the same tcp tuple.
https://stackoverflow.com/questions/14388706/how-do-so-reuseaddr-and-so-reuseport-differ

Add a generic way to specify socket options when creating a listen socket
with tcp_listener.

This allows use to remove the current hack that the test are always
build without NDEBUG regardless of the meson buildtype.

Which is fact fixes the failing io tests in release builds.
Because Future.hpp and Future.cpp see the same version of NDEBUG.