lib/59850: manual pages proplib code examples refer to deprecated functions

[coypu%sdf.org@localhost]

>Number:         59850
>Category:       lib
>Synopsis:       manual pages proplib code examples refer to deprecated functions
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    lib-bug-people
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Sun Dec 21 00:35:00 +0000 2025
>Originator:     coypu
>Release:        NetBSD 11 BETA
>Organization:
>Environment:
NetBSD  11.0_BETA NetBSD 11.0_BETA (GENERIC) #0: Mon Oct 20 14:11:07 UTC 2025  mkrepro%mkrepro.NetBSD.org@localhost:/usr/src/sys/arch/amd64/compile/GENERIC amd64

>Description:
Try to follow manual page example from "man envsys", get deprecated function warning:
main.c:(.text+0xaa): warning: this program uses prop_string_create_cstring_nocopy(), which is deprecated; use prop_string_create_nocopy() instead.


there seem to be other references to this function in other manual pages too.
>How-To-Repeat:

>Fix: