shared/bus-util: drop trusted annotation from bus_open_system_watch_bind_with_descrip...

shared/bus-util: drop trusted annotation from bus_open_system_watch_bind_with_description()

https://bugzilla.redhat.com/show_bug.cgi?id=1746057

This only affects systemd-resolved. bus_open_system_watch_bind_with_description()
is also used in timesyncd, but it has no methods, only read-only properties, and
in networkd, but it annotates all methods with SD_BUS_VTABLE_UNPRIVILEGED and does
polkit checks.

(cherry picked from commit 35e528018f315798d3bffcb592b32a0d8f5162bd)

Gbp-Pq: Name shared-bus-util-drop-trusted-annotation-from-bus_open_sys.patch