[hnswlib] Fix Index.get_items return types (#16578)

Author: Blacksujit

stubs/hnswlib/hnswlib.pyi

@@ -25,13 +25,15 @@ class Index:
     def get_ids_list(self) -> list[int]: ...
 
     @overload
-    def get_items(self, ids: ArrayLike | None = ..., return_type: Literal["list"] = ...) -> list[float]: ...
+    def get_items(self, ids: ArrayLike | None = None, return_type: Literal["numpy"] = "numpy") -> NDArray[np.float32]: ...
     @overload
-    def get_items(self, ids: ArrayLike | None = ..., return_type: Literal["numpy"] = ...) -> NDArray[np.float32]: ...
+    def get_items(self, ids: ArrayLike | None, return_type: Literal["list"]) -> list[list[float]]: ...
+    @overload
+    def get_items(self, ids: ArrayLike | None = None, *, return_type: Literal["list"]) -> list[list[float]]: ...
     @overload
     def get_items(
         self, ids: ArrayLike | None = None, return_type: Literal["numpy", "list"] = "numpy"
-    ) -> NDArray[np.float32] | list[float]: ...
+    ) -> NDArray[np.float32] | list[list[float]]: ...
 
     def get_max_elements(self) -> int: ...
     def index_file_size(self) -> int: ...