add rwkv version field

backend-python/rwkv_pip/cpp/model.py

@@ -9,6 +9,9 @@ class RWKV:
         self.model = rwkv_cpp_model.RWKVModel(self.library, model_path)
         self.w = {}  # fake weight
         self.w["emb.weight"] = [0] * self.model.n_vocab
+        self.version = (
+            self.model.arch_version_major + self.model.arch_version_minor / 10
+        )
 
     def forward(self, tokens: List[int], state: Union[Any, None] = None):
         return self.model.eval_sequence_in_chunks(tokens, state, use_numpy=True)