Update reboot_pending/reboot_pending.dsc.resource.json

Co-authored-by: Mikey Lombardi (He/Him) <michael.t.lombardi@gmail.com>

Author: Andrew

reboot_pending/reboot_pending.dsc.resource.json

@@ -19,7 +19,8 @@
       "type": "null",
       "properties": {
         "RebootPending": {
-            "type": "boolean"
+            "type": "boolean",
+            "readOnly": true
         }
       }
     }