feat(dbus): Add InterfaceRevpiConfig to DBus interfaces list

Added the InterfaceRevpiConfig class to the list of DBus interfaces in
`bus_provider.py`. This ensures the new system configuration interface
is properly registered and accessible.

src/revpi_middleware/dbus_middleware1/bus_provider.py

@@ -10,6 +10,7 @@ from pydbus import SessionBus, SystemBus
 
 from . import REVPI_DBUS_NAME
 from .process_image import InterfacePiControl
+from .system_config import InterfaceRevpiConfig
 
 log = getLogger(__name__)
 
@@ -41,6 +42,7 @@ class BusProvider(Thread):
         #   ("Subdir2/Whatever", Example())
         lst_interfaces = [
             InterfacePiControl(self.picontrol_device, self.config_rsc),
+            InterfaceRevpiConfig(),
         ]
 
         try: