Refs #37696 - Don't run sub facet fact parser on non registered hosts

* When a host that is not registered with subscription manager tries to update facts we get an error "Content host must be unregistered before performing this action"

This change causes the fact parser to skip if the host does not have a subscription facet, also changing the db column from int4 to boolean

app/models/katello/host/subscription_facet.rb

@@ -298,11 +298,12 @@ def backend_update_needed?
       end
 
       def self.populate_fields_from_facts(host, parser, _type, _source_proxy)
+        return unless host.subscription_facet # skip method if the host is not a registered host
         has_convert2rhel = parser.facts.key?('conversions.env.CONVERT2RHEL_THROUGH_FOREMAN')
         # Add in custom convert2rhel fact if system was converted using convert2rhel through Katello
         # We want the value nil unless the custom fact is present otherwise we get a 0 in the database which if debugging
         # might make you think it was converted2rhel but not with satellite, that is why I have the tenary below.
-        facet = host.subscription_facet || host.build_subscription_facet
+        facet = host.subscription_facet
         facet.attributes = {
           convert2rhel_through_foreman: has_convert2rhel ? ::Foreman::Cast.to_bool(parser.facts['conversions.env.CONVERT2RHEL_THROUGH_FOREMAN']) : nil
         }.compact

db/migrate/20240815215102_change_convert2_rhel_to_boolean.rb

@@ -0,0 +1,9 @@
+class ChangeConvert2RhelToBoolean < ActiveRecord::Migration[6.1]
+  def up
+    change_column :katello_subscription_facets, :convert2rhel_through_foreman, :boolean, using: 'convert2rhel_through_foreman::boolean'
+  end
+
+  def down
+    change_column :katello_subscription_facets, :convert2rhel_through_foreman, :integer, using: 'convert2rhel_through_foreman::integer'
+  end
+end