Fix: Cleanup Dell OS10 readiness check

The Dell OS10 readiness check was just a wait followed by SSH check.
The wait is now implemented with the 'netlab_start_exec' group var,
and the SSH check with the 'netlab_ready' group var

Author: ipspace

netsim/ansible/tasks/readiness-check/dellos10-clab.yml

@@ -90,7 +90,8 @@ clab:
     ansible_ssh_pass: admin
     netlab_check_retries: 40
     netlab_check_delay: 10
-    netlab_initial_delay: 30
+    netlab_start_exec: [ sleep 15 ]     # Dell OS10 needs a bit of time to wake from its slumber
+    netlab_ready: [ ssh ]
 libvirt:
   image: dell/os10
   build: https://netlab.tools/labs/dellos10/