remove deprecated Termios type alias

This was deprecated in 80ddd80 (v0.5.0).

Signed-off-by: Sebastiaan van Stijn <github@gone.nl>

Author: thaJeztah

termios_unix.go

@@ -7,11 +7,6 @@ import (
 	"golang.org/x/sys/unix"
 )
 
-// Termios is the Unix API for terminal I/O.
-//
-// Deprecated: use [unix.Termios].
-type Termios = unix.Termios
-
 func makeRaw(fd uintptr) (*State, error) {
 	termios, err := tcget(fd)
 	if err != nil {