multimedia/wireplumber: backport devel/glib20 fix from 0.5.0

In file included from ../src/modules/wireplumber.cpp:1:
In file included from ../include/modules/wireplumber.hpp:9:
In file included from ../include/ALabel.hpp:4:
In file included from /usr/local/include/gtkmm-3.0/gtkmm/label.h:27:
In file included from /usr/local/include/gtkmm-3.0/gtkmm/misc.h:27:
In file included from /usr/local/include/gtkmm-3.0/gtkmm/widget.h:31:
In file included from /usr/local/include/pangomm-1.4/pangomm/context.h:31:
In file included from /usr/local/include/glibmm-2.4/glibmm/object.h:30:
/usr/local/include/glibmm-2.4/glibmm/wrap.h:92:7: error: use of undeclared identifier 'WP_LOCAL_LOG_TOPIC'

92 |       g_warning("Glib::wrap_auto_interface(): The C++ instance (%s) does not dynamic_cast to the "
   |       ^

/usr/local/include/glib-2.0/glib/gmessages.h:362:32: note: expanded from macro 'g_warning'

362 | #define g_warning(...)  g_log (G_LOG_DOMAIN,         \
    |                                ^

/usr/local/include/wireplumber-0.5/wp/log.h:65:23: note: expanded from macro 'G_LOG_DOMAIN'

65 | #define G_LOG_DOMAIN (WP_LOCAL_LOG_TOPIC->topic_name)
   |                       ^