fix: a few certification patches

Summary

fix 63 major gamayun issues

Ensure that

• New code is covered by tests
• API is documented
• Changelog is up to date
• (if Lua API changed) Lua API version is bumped in luamod.rs
• (if necessary) A follow-up doc issue is created in picodata/docs and linked here

certification_patches/curl_libssh2.patch

+diff --git a/lib/vssh/libssh2.c b/lib/vssh/libssh2.c
+index ce9229f8f..4aef2ae70 100644
+--- a/lib/vssh/libssh2.c
++++ b/lib/vssh/libssh2.c
+@@ -723,11 +723,11 @@ static CURLcode ssh_check_fingerprint(struct Curl_easy *data)
+      */
+     if((pub_pos != b64_pos) ||
+        strncmp(fingerprint_b64, pubkey_sha256, pub_pos)) {
+-      free(fingerprint_b64);
+ 
+       failf(data,
+             "Denied establishing ssh session: mismatch sha256 fingerprint. "
+             "Remote %s is not equal to %s", fingerprint_b64, pubkey_sha256);
++      free(fingerprint_b64);
+       state(data, SSH_SESSION_FREE);
+       sshc->actualcode = CURLE_PEER_FAILED_VERIFICATION;
+       return sshc->actualcode;