doc: drop the device capabilities
These were removed in
@@ -147,15 +147,6 @@ known to ratbagd.
The device's name, suitable for presentation to the user.
-.. attribute:: Capabilities
-
- :type: au
- :flags: read-only, constant
-
- The capabilities supported by this device. see
- :cpp:enum:`ratbag_device_capability` in libratbag-enums.h for the
- list of permissible capabilities.
-
.. attribute:: Profiles
:type: ao
