add in err msg: no argsort

Author: cakedev0

src/array_api_extra/_delegation.py

@@ -438,7 +438,7 @@ def argpartition(
     if xp is None:
         xp = array_namespace(a)
     if is_pydata_sparse_namespace(xp):
-        msg = "Not implemented for sparse backend"
+        msg = "Not implemented for sparse backend: no argsort"
         raise NotImplementedError(msg)
     if a.ndim < 1:
         msg = "`a` must be at least 1-dimensional"