refactor: defuse dpa2 register_buffer trap for tebd compression slot

deepmd/pt_expt/descriptor/dpa2.py:_store_type_embd_data still called
torch.nn.Module.register_buffer(self, "type_embd_data", ...) directly,
the same raw pattern fixed for dpa1/se_t_tebd in the previous commit.
DescrptDPA2 (dpmodel) doesn't declare the type_embd_data slot yet, so
this was purely defensive, but it removes the landmine for whichever
future change declares it there. Swap to the existing
register_buffer_replacing_slot() helper in pt_expt/common.py.

Author: Han Wang

deepmd/pt_expt/descriptor/dpa2.py

@@ -21,6 +21,7 @@
     remap_atype_to_padding,
 )
 from deepmd.pt_expt.common import (
+    register_buffer_replacing_slot,
     torch_module,
 )
 from deepmd.pt_expt.descriptor.base_descriptor import (
@@ -284,7 +285,7 @@ def _store_type_embd_data(self) -> None:
                     self.repinit.embeddings_strip[0].call(two_side_embd).detach()
                 )
 
-            torch.nn.Module.register_buffer(self, "type_embd_data", embd_tensor)
+            register_buffer_replacing_slot(self, "type_embd_data", embd_tensor)
 
     @cast_precision
     def call(