standards/56663: Disable RANDOM variable in sh(1) POSIX mode

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>Number:         56663
>Category:       standards
>Synopsis:       Disable RANDOM variable in sh(1) POSIX mode
>Confidential:   no
>Severity:       non-critical
>Priority:       low
>Responsible:    standards-manager
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Mon Jan 24 07:35:00 +0000 2022
>Originator:     yetoo
>Release:        NetBSD 9.99.93 Jan 14 build
>Organization:
>Environment:
NetBSD alarm.lan 9.99.93 NetBSD 9.99.93 (GENERIC) #0: Fri Jan 14 07:40:52 UTC 2022  mkrepro%mkrepro.NetBSD.org@localhost:/usr/src/sys/arch/i386/compile/GENERIC i386
>Description:
The RANDOM environment variable is not POSIX compliant and should be disabled in posix mode.
>How-To-Repeat:
1. Enter /bin/sh
2. execute set -o posix
3. verify posix is set via set -o
4. echo $RANDOM
5. Notice the number that is generated
>Fix: