Add GigaAM NeMo transducer model for Russian ASR (#1467)

scripts/nemo/GigaAM/export-onnx-ctc.py

@@ -75,6 +75,7 @@ def add_meta_data(filename: str, meta_data: Dict[str, str]):
     onnx.save(model, filename)
 
 
+@torch.no_grad()
 def main():
     model = EncDecCTCModel.from_config_file("./ctc_model_config.yaml")
     ckpt = torch.load("./ctc_model_weights.ckpt", map_location="cpu")