fix(pt): move entry point from deepmd.pt.model to deepmd.pt (deep…

…modeling#4146)

`deepmd.pt` should be a more reasonable one to load the plugins.

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

## Summary by CodeRabbit

- **New Features**
- Enhanced initialization process for the `deepmd.pt` module, allowing
for improved dynamic loading and configuration.
  
- **Refactor**
- Removed unnecessary imports and function calls related to entry point
loading in the `deepmd.pt.model` module, streamlining the module's
initialization.

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

Signed-off-by: Jinzhe Zeng <jinzhe.zeng@rutgers.edu>

deepmd/pt/__init__.py

@@ -4,6 +4,11 @@
 from deepmd.pt.cxx_op import (
     ENABLE_CUSTOMIZED_OP,
 )
+from deepmd.utils.entry_point import (
+    load_entry_point,
+)
+
+load_entry_point("deepmd.pt")
 
 __all__ = [
     "ENABLE_CUSTOMIZED_OP",

deepmd/pt/model/__init__.py

@@ -1,6 +1 @@
 # SPDX-License-Identifier: LGPL-3.0-or-later
-from deepmd.utils.entry_point import (
-    load_entry_point,
-)
-
-load_entry_point("deepmd.pt")