fix: data type of nloc, nall-nloc in the input of border_op (#4653)

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

- **Refactor**
- Updated internal processing to explicitly assign certain computational
operations to run on the CPU. This change clarifies execution behavior
and enhances consistency in data handling while preserving all existing
functionalities for end-users.

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

Co-authored-by: Han Wang <wang_han@iapcm.ac.cn>
(cherry picked from commit d040d08)
Signed-off-by: Jinzhe Zeng <jinzhe.zeng@ustc.edu.cn>

Author: 2 people

deepmd/pt/model/descriptor/repformers.py

@@ -491,13 +491,13 @@ def forward(
                     torch.tensor(
                         real_nloc,
                         dtype=torch.int32,
-                        device=env.DEVICE,
-                    ),  # should be int of c++
+                        device=torch.device("cpu"),
+                    ),  # should be int of c++, placed on cpu
                     torch.tensor(
                         real_nall - real_nloc,
                         dtype=torch.int32,
-                        device=env.DEVICE,
-                    ),  # should be int of c++
+                        device=torch.device("cpu"),
+                    ),  # should be int of c++, placed on cpu
                 )
                 g1_ext = ret[0].unsqueeze(0)
                 if has_spin: