gh-127076: Disable strace tests under LD_PRELOAD (#127086)

Distribution tooling (ex. sandbox on Gentoo and fakeroot on Debian) uses
LD_PRELOAD to intercept system calls and potentially modify them when
building. These tools can change the set of system calls, so disable
system call testing under these cases.

Co-authored-by: Michał Górny <mgorny@gentoo.org>