fix: use sensible default for runs-on

This new value is inline with the tags applied to the runners deployed during kayobe-automation deployment.

roles/github/defaults/main.yml

@@ -5,7 +5,7 @@ github_environment_selector:
 
 github_kayobe_environments: []
 
-github_runs_on: [self-hosted]
+github_runs_on: [kayobe, openstack]
 
 github_registry: {}