curl: CVE-2026-80229: OpenSSL provider use-after-free

Summary When CURLOPTSSLENGINE is set e.g. "default" on OpenSSL 3.x, osslsetprovider line 1791 allocates a per-handle OSSLLIBCTX and stores it in data-state.libctx. During TLS connection setup, SSLCTXnewex line 3750 receives this library context and embeds a pointer to it inside the newly created...