openssl: Import OpenSSL 3.0.15.
This release incorporates the following bug fixes and mitigations:
- Fixed possible denial of service in X.509 name checks ([CVE-2024-6119])
- Fixed possible buffer overread in SSL_select_next_proto() ([CVE-2024-5535])
Release notes can be found at:
https://openssl-library.org/news/openssl-3.0-notes/index.html