update coords after shift_orig_zero (#803)

Hi,

I think this part of the code was attempting to modify local variables
(`ii`) rather than the actual array elements in `self.data["coords"]`.

Before:
```
@post_funcs.register("shift_orig_zero")
    def _shift_orig_zero(self):
        for ff in self.data["coords"]:
             for ii in ff:
                 ii = ii - self.data["orig"]
                 ...
```
After:
```
...
self.data["coords"] = self.data["coords"] - self.data["orig"]
```

<!-- This is an auto-generated comment: release notes by coderabbit.ai
-->

## Summary by CodeRabbit

- **Refactor**
- Enhanced the efficiency of coordinate adjustments for improved
performance on larger datasets.

<!-- end of auto-generated comment: release notes by coderabbit.ai -->

Signed-off-by: .Del <[email protected]>

Author: zrzrv5

dpdata/system.py

@@ -710,9 +710,7 @@ def affine_map(self, trans, f_idx: int | numbers.Integral = 0):
 
     @post_funcs.register("shift_orig_zero")
     def _shift_orig_zero(self):
-        for ff in self.data["coords"]:
-            for ii in ff:
-                ii = ii - self.data["orig"]
+        self.data["coords"] = self.data["coords"] - self.data["orig"]
         self.data["orig"] = self.data["orig"] - self.data["orig"]
         assert (np.zeros([3]) == self.data["orig"]).all()