net/dhcpcd: Update to 9.1.2

Also disable udev support in CONFIGURE_ARGS, given that FreeBSD has
the function udev_device_new_from_subsystem_sysname if the module
libudev-devd is installed, but it is not implemented.

PR: 247144
Reported by: Greg V <greg@unrelenting.technology>
Reviewed by: Roy Marples <roy@marples.name>