This commit fixes the handling of POSIX permissions on Windows in the
spawner tests. Since POSIX permissions do not exist there, we first have
to check if we are on a filesystem that supports POSIX or not before
attempting to set the permissions.
Today in the codebase we refer to seccomp everywhere instead of system
call filter even if we are not specifically referring to Linux. This
commit is a purely mechanical change to refer to system call filter
where appropriate instead of the general seccomp, and only leaves
seccomp in place when actually referring to the Linux implementation.
Relates #22243
Jason Tedor
Nik Everett
David Roberts