main/openssh: force static linking against utmps and skalibs

Since openssh-9.9_p1-r0, openssh is linked dynamically against skalibs and statically against utmps (see the dependency tracing output in the build log). This is not intended as it should be statically linked against both. This commit adds a more fancy linker command-line to ensure that this is the case.

Furthermore, in the future it may be desirable to only link sshd-session against utmps-dev and not the entire thing.