fix: Use variant_type instead of hard coded boolean

Signed-off-by: Marc Kittner <m.kittner@kunbus.com>

src/revpi_middleware/ios1/interface_ios.py

@@ -56,7 +56,7 @@ class InterfaceIoManager:
             interface = self._dc_io_interfaces[io_name]
             if ct.changed(interface.io):
                 interface.emit_io_change()
-                self.IoChanged(interface.io.name, Variant("b", interface.io.value))
+                self.IoChanged(interface.io.name, Variant(interface.variant_type, interface.io.value))
 
     def _get_io_path(self, io_name: str) -> str:
         return f"{REVPI_DBUS_BASE_PATH}/io/{io_name}"