klippy: Verify nothing attempts to pause in the klippy:ready event

Signed-off-by: Kevin O'Connor <kevin@koconnor.net>

klippy/klippy.py

@@ -158,10 +158,11 @@ class Printer:
             return
         try:
             self._set_state(message_ready)
-            for cb in self.event_handlers.get("klippy:ready", []):
-                if self.state_message is not message_ready:
-                    return
-                cb()
+            with self.reactor.assert_no_pause():
+                for cb in self.event_handlers.get("klippy:ready", []):
+                    if self.state_message is not message_ready:
+                        return
+                    cb()
         except Exception as e:
             logging.exception("Unhandled exception during ready callback")
             self.invoke_shutdown("Internal error during ready callback: %s"