Yubikey OTP support disabled in -current

Yubikey OTP support has been disabled in -current. The commit message explains the rationale:

CVSROOT:	/cvs
Module name:	src
Changes by:	deraadt@cvs.openbsd.org	2025/08/14 08:39:44

Modified files:
	sys/dev/usb    : ukbd.c 

Log message:
Most Yubikey ship with OTP support enabled out of the box (and generate
accidental output like cccccblddbkhelgbdjuughbjdcvrddggdcjvricrriuk).
Yubikey re-configuration requires crazy buggy and fragile tools using crazy
usb feature support, and therefore OTP disabling is very annoying.  We
make a policy decision to not attach these as keyboards anymore, because a
majority of users just want the FIDO functionality.  If you want to use OTP,
buy a different device from a different vendor or convince Yubikey to
significantly improve their tooling.
idea from kettenis

To be clear: this affects only the keyboard attachment of only Yubico devices. Therefore:

• USB security devices from other vendors are not affected.
• FIDO functionality of Yubikeys (and Yubico security keys) is not affected.
• login_yubikey(8) can no longer be used for local authentication purposes, but will still function for authentication of remote clients (so long as they support Yubikey OTP).

Running a patched kernel is the only way [at present] to reverse this change.