[devel-noble] set QT_LOGGING_RULES to silence Connections and Binding.restoreMode deprecations warning

Lots of components and apps haven't been migrated yet, and it would be quite a churn to migrate them all. We don't want to litter log on end users' devices (where they can't do anything). Also, old syntax is deprecated in Qt 5.15 but new syntax isn't available in Qt 5.12; lots of apps would want to stay compatible with Qt 5.12 on 20.04 for a while more.