comment out PipelineMixedPrecisionPlugin to fix conversion error

Author: xingyaoww

scripts/checkpoint_converters/convert_mistral_7b_hf_to_nemo.py

@@ -178,8 +178,8 @@ def convert(args):
 
         if nemo_config.get('megatron_amp_O2', False):
             plugins.append(MegatronHalfPrecisionPlugin(precision=plugin_precision, device='cuda', scaler=scaler))
-        else:
-            plugins.append(PipelineMixedPrecisionPlugin(precision=plugin_precision, device='cuda', scaler=scaler))
+        # else:
+        #     plugins.append(PipelineMixedPrecisionPlugin(precision=plugin_precision, device='cuda', scaler=scaler))
 
     if precision == 32:
         dtype = torch.float32