bootc-publish-rhsm-facts: Add ConditionPathExists=/run/ostree-booted

Right now this service fails in `bcvk run-ephemeral`, but
also likely fails in any non-bootc system that has `subscription-manager`
installed.

Author: cgwalters

systemd/bootc-publish-rhsm-facts.service

@@ -2,6 +2,11 @@
 Description=Publish bootc facts to Red Hat Subscription Manager
 Documentation=man:bootc(8)
 ConditionPathExists=/etc/rhsm/facts
+# TODO: Also consider something like this for composefs...
+# or alternatively, add a bootc service that's like
+# ostree-boot-complete.service that we run unconditionally on
+# boot which triggers these things.
+ConditionPathExists=/run/ostree-booted
 
 [Service]
 Type=oneshot