x11/libinput: Update to 1.12.6

Update libinput to 1.12.6.
This is the last remaining piece to bring us basically up to date with
upstream input stack.

PR: 222905
Reported by: Greg V (original version)
Obtained from: FreeBSDDesktop development repo

		https://github.com/FreeBSDDesktop/freebsd-ports/tree/feature/input-ports

Tested by: tcberner (kde@), andrnils@gmail.com
Sponsored by: B3 Init (zeising)