community/libwacom: upgrade to 2.9.0

https://github.com/linuxwacom/libwacom/compare/libwacom-2.8.0...libwacom-2.9.0

Changelog

libwacom 2.9
- New Devices:
  - Wacom Cintiq Pro 22, Cintiq Pro 17, DTC121, DTH134, ISDv4 58B7
  - XP Pen Artist 13.3, XP Pen G430s
- Tablet data file changes:
  - A new KeyCodes=<evdev codes> entry is now supported
  - EvdevCodes=<evdev codes> now supports evdev code names (e.g. BTN_0)
  - The Buttons=<int> entry is no longer supported (it is
    inferred from the Buttons section)
- New APIs:
  - libwacom_get_num_keys() for number of supported key codes
- License correction: text used was HPND, not MIT/Expat

https://github.com/linuxwacom/libwacom/blob/628e3013948401750f3f1cc5b919e5e5e908c7cc/NEWS