x11/aminal: Unbreak on aarch64

github.com/liamg/aminal/vendor/github.com/kr/pty

vendor/github.com/kr/pty/pty_freebsd.go:50:20: undefined: fiodgnameArg
vendor/github.com/kr/pty/pty_freebsd.go:63:12: undefined: _C_SPECNAMELEN
vendor/github.com/kr/pty/pty_freebsd.go:66:9: undefined: fiodgnameArg

PR: 243813
Approved by: yuri (maintainer), manu (mentor)