src: fix the false isatty() issue on IBMi

On IBMi PASE isatty() always returns true for stdin, stdout and stderr.
Use ioctl() instead to identify whether it's actually a TTY.

PR-URL: https://github.com/nodejs/node/pull/30829


Reviewed-By: Richard Lau <riclau@uk.ibm.com>
Reviewed-By: David Carlier <devnexen@gmail.com>
Reviewed-By: Rich Trott <rtrott@gmail.com>
Reviewed-By: Ruben Bridgewater <ruben@bridgewater.de>
Reviewed-By: Michael Dawson <michael_dawson@ca.ibm.com>