[BUG] DPA-2 model cannot be converted to .dp format

[njzjz]

Bug summary

When converting a DPA-2 .pth model to .dp format, an error is thrown (see below).

The reason is that we assume all NumPy arrays are in the @variables keys in the serialization data (see #2982). However, it seems that some arrays are stored out of the @variables.

deepmd-kit/deepmd/pt/model/descriptor/repformer_layer.py

Lines 1380 to 1388 in ff04d8b

	if self.update_style == "res_residual":
	data.update(
	{
	"g1_residual": [to_numpy_array(t) for t in self.g1_residual],
	"g2_residual": [to_numpy_array(t) for t in self.g2_residual],
	"h2_residual": [to_numpy_array(t) for t in self.h2_residual],
	}
	)
	return data

We don't have a check to check it.

We need to discuss whether we insist on this rule.

DeePMD-kit Version

devel

Backend and its version

How did you download the software?

Built from source

Input Files, Running Commands, Error Log, etc.

Traceback (most recent call last):
  File "/home/jz748/anaconda3/bin/dp", line 8, in <module>
    sys.exit(main())
  File "/home/jz748/codes/deepmd-kit/deepmd/main.py", line 926, in main
    deepmd_main(args)
  File "/home/jz748/codes/deepmd-kit/deepmd/entrypoints/main.py", line 86, in main
    convert_backend(**dict_args)
  File "/home/jz748/codes/deepmd-kit/deepmd/entrypoints/convert_backend.py", line 27, in convert_backend
    out_hook(OUTPUT, data)
  File "/home/jz748/codes/deepmd-kit/deepmd/dpmodel/utils/serialization.py", line 106, in save_dp_model
    f.attrs["json"] = json.dumps(save_dict, separators=(",", ":"))
  File "/home/jz748/anaconda3/lib/python3.10/json/__init__.py", line 238, in dumps
    **kw).encode(obj)
  File "/home/jz748/anaconda3/lib/python3.10/json/encoder.py", line 199, in encode
    chunks = self.iterencode(o, _one_shot=True)
  File "/home/jz748/anaconda3/lib/python3.10/json/encoder.py", line 257, in iterencode
    return _iterencode(o, 0)
  File "/home/jz748/anaconda3/lib/python3.10/json/encoder.py", line 179, in default
    raise TypeError(f'Object of type {o.__class__.__name__} '
TypeError: Object of type ndarray is not JSON serializable

Steps to Reproduce

cd examples/water/dpa2
# change the number of steps to 0
dp --pt train input_torch_small.json
dp --pt freeze
dp convert-backend frozen_model.pth frozen_model.dp

Further Information, Files, and Links

No response