Log Message:
libxkbcommon: update to 1.2.1.

libxkbcommon 1.2.1 - 2021-04-07
==================

- Fix `xkb_x11_keymap_new_from_device()` failing when the keymap contains key
  types with missing level names, like the one used by the `numpad:mac` option
  in xkeyboard-config. Regressed in 1.2.0.