bip-340: set all_passed=False on key generation mismatch

Fix test harness to correctly fail when public key generation does not match the expected vector. Previously, the “Failed key generation” branch only printed diagnostics without updating all_passed, leading to a false-positive overall test result. This is a bug because a keygen mismatch indicates an implementation error that must cause the test run to fail, consistent with how other failures in the harness set all_passed = False.

Specification