search for: sk_free_sk_resident_key

Hi, Sometimes, users might find that the `ssh-sk-helper` crashes after enrolling a new key when using external SK libraries. Currently, the memory returned by SK APIs is freed by the host, but external libraries may have their own methods of handling memory. For instance some external libraries are linked against a foreign libc statically. As a result, the `ssh-sk-helper` would have issues if