Rename `model_id` to `model.id` (#8447)

Co-authored-by: Glenn Jocher <glenn.jocher@ultralytics.com>

ultralytics/utils/callbacks/hub.py

@@ -46,7 +46,7 @@ def on_model_save(trainer):
         # Upload checkpoints with rate limiting
         is_best = trainer.best_fitness == trainer.fitness
         if time() - session.timers["ckpt"] > session.rate_limits["ckpt"]:
-            LOGGER.info(f"{PREFIX}Uploading checkpoint {HUB_WEB_ROOT}/models/{session.model_id}")
+            LOGGER.info(f"{PREFIX}Uploading checkpoint {HUB_WEB_ROOT}/models/{session.model.id}")
             session.upload_model(trainer.epoch, trainer.last, is_best)
             session.timers["ckpt"] = time()  # reset timer