feat(pt/dp/jax/xp): add DPA3 descriptor

deepmd/dpmodel/descriptor/__init__.py

@@ -5,6 +5,9 @@
 from .dpa2 import (
     DescrptDPA2,
 )
+from .dpa3 import (
+    DescrptDPA3,
+)
 from .hybrid import (
     DescrptHybrid,
 )
@@ -30,6 +33,7 @@
 __all__ = [
     "DescrptDPA1",
     "DescrptDPA2",
+    "DescrptDPA3",
     "DescrptHybrid",
     "DescrptSeA",
     "DescrptSeAttenV2",