test: add test for uid/gid setting in spawn
Checklist
-
tests and code linting passes -
the commit message follows commit guidelines
Affected core subsystem(s)
test child_process
Description of change
Remove a disabled test in favor of one that expects an error.
This validates (somewhat) that the underlying code is calling the correct system call for setting UID and GID. Unlike the formerly disabled test, it does not try to validate that the system UID/GID setting works.