fix: SSH clients misses Qubes network integration

Although the dev qube doesn't need it as it use a TCP proxy, every
normal SSH setup requires it.

salt/sys-ssh-agent/install-client.sls

@@ -20,6 +20,8 @@ include:
     - install_recommends: False
     - skip_suggestions: True
     - pkgs:
+      - qubes-core-agent-networking
+      - ca-certificates
       - socat
       - man-db