"pixdim" and "affine" not updated by Spacingd transform

[kate-sann5100]

Describe the bug
The current version of Spacingd did not update the "pixdim" and "affine" (so "affine" equals "original")in metadict. This could be confusing.

To Reproduce
N/A

Expected behavior
"pixdim" and "affine" should be updated.

Screenshots
N/A

Environment
N/A

Additional context
monai 0.9.0 with the following implementation does not have this issue.

    def __call__(
        self, data: Mapping[Union[Hashable, str], Dict[str, NdarrayOrTensor]]
    ) -> Dict[Hashable, NdarrayOrTensor]:
        d: Dict = dict(data)
        for key, mode, padding_mode, align_corners, dtype, meta_key, meta_key_postfix in self.key_iterator(
            d, self.mode, self.padding_mode, self.align_corners, self.dtype, self.meta_keys, self.meta_key_postfix
        ):
            meta_key = meta_key or f"{key}_{meta_key_postfix}"
            # create metadata if necessary
            if meta_key not in d:
                d[meta_key] = {"affine": None}
            meta_data = d[meta_key]
            # resample array of each corresponding key
            # using affine fetched from d[affine_key]
            original_spatial_shape = d[key].shape[1:]
            d[key], old_affine, new_affine = self.spacing_transform(
                data_array=d[key],
                affine=meta_data["affine"],
                mode=mode,
                padding_mode=padding_mode,
                align_corners=align_corners,
                dtype=dtype,
            )
            self.push_transform(
                d,
                key,
                extra_info={
                    "meta_key": meta_key,
                    "old_affine": old_affine,
                    "mode": mode.value if isinstance(mode, Enum) else mode,
                    "padding_mode": padding_mode.value if isinstance(padding_mode, Enum) else padding_mode,
                    "align_corners": align_corners if align_corners is not None else TraceKeys.NONE,
                },
                orig_size=original_spatial_shape,
            )
            # set the 'affine' key
            meta_data["affine"] = new_affine
        return d

[KumoLiu]

Hi @kate-sann5100, meta_dict is deprecated in this transform since 0.9.0, so the meta_dict won't be updated.

MONAI/monai/transforms/spatial/dictionary.py

Lines 323 to 324 in 97918e4

	@deprecated_arg(name="meta_keys", since="0.9")
	@deprecated_arg(name="meta_key_postfix", since="0.9")

You can get the new affine by using data.affine.
Thanks!