tests: Start and terminate D-Bus orderly
Start the dconf service after starting D-Bus, and ignore the SIGTERM indirectly received when terminating the dedicated D-Bus service.
Fixes tests/CI with recent python3-dbusmock present in F39.
Start the dconf service after starting D-Bus, and ignore the SIGTERM indirectly received when terminating the dedicated D-Bus service.
Fixes tests/CI with recent python3-dbusmock present in F39.