Skip shlibload tests if no-atexit is configured

Skip shlibload tests if no-atexit is configured

the shared library load tests fail if no-atexit is configured.  The
entire test suite relies on atexit handling to indicate an at exit
handler has run, by producing a file that the test recipe then reads.
With no-atexit that never happens, and the test fails

If no-atexit is specified, skip all the tests

Reviewed-by: Matt Caswell <matt@openssl.org>
Reviewed-by: Tomas Mraz <tomas@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/23523)