Suppress 'Loaded N models' message in batch mode

The message is now suppressed when using --model-list-batch to make
the output cleaner for scripts.

videogen.py

@@ -2558,7 +2558,7 @@ def print_search_results(results, args):
 MODELS = {}
 
 # Check if JSON output is requested (for suppressing log messages)
-_json_output = "--json" in sys.argv
+_json_output = "--json" in sys.argv or "--model-list-batch" in sys.argv
 
 # Load external models config
 _external_models = load_models_config()