Add atexit configuration option to using atexit() in libcrypto at build-time.

Add atexit configuration option to using atexit() in libcrypto at build-time.

This fixes an issue with a mix of atexit() usage in DLL and statically linked
libcrypto that came out in the test suite on NonStop, which has slightly
different DLL unload processing semantics compared to Linux. The change
allows a build configuration to select whether to register OPENSSL_cleanup()
with atexit() or not, so avoid situations where atexit() registration causes
SIGSEGV.

INSTALL.md and CHANGES.md have been modified to include and describe this
option.

The no-atexit option has been added to .github/workflows/run-checker-daily.yml.

Fixes: #23135
Signed-of-by: Randall S. Becker <randall.becker@nexbridge.ca>
Reviewed-by: Matt Caswell <matt@openssl.org>
Reviewed-by: Neil Horman <nhorman@openssl.org>
Reviewed-by: Todd Short <todd.short@me.com>
(Merged from https://github.com/openssl/openssl/pull/23394)